waawm 


PRACTICAL  TALKS 
ON  FARM 

ENGINEERING 

RP  Clarkson 


yf€ar<?Aalv< 


So  tWt^At^en^ 


\  * 


^HAS.B.UAURIATc^ 


PRACTICAL  TALKS  ON 
FARM  ENGINEERING 


PRACTICAL  TALKS  ON 
FARM    ENGINEERING 

A  Simple  Explanation  of  Many  Everyday 

Problems  in  Farm  Engineering  and  Farm 

Mechanics  Written  in  a  Readable 

Style  for  the  Practical  Farmer 


BY 

R.  P.  CLARKSON,  B.  S. 

PROFESSOR  OF  ENGINEERING,  ACADIA  UNIVERSITY 

CONSULTING  ENGINEER 

ENGINEERING  CORRESPONDENT  OF  THE  "RURAL  NEW-VORKEr" 


Illustrated  from  photographs  and  diagrams 


Garden  City  New  York 

DOUBLEDAY,  PAGE  &  COMPANY 

1915 


Copyright,  1915,  by 
DOUBLEDAY,  PAGE  &  COMPANY 

All  rights  reserved,  including  that  of 

translation  into  foreign  languages, 

including  the  Scandinavian 


ACKNOWLEDGMENTS 

The  author  and  publishers  wish  to  extend  to  the 
following  firms  acknowledgment  and  thanks  for  their 
hearty  cooperation: 

AVERY  COMPANY,  PEORIA,  ILLINOIS 

CANADA  CEMENT  COMPANY,  MONTREAL,  QUEBEC 

CROSBY  STEAM  GAUGE  AND  VALVE  COMPANY, 

BOSTON,  MASS. 

DETROIT  ENGINE  COMPANY,  DETROIT,  MICH. 

DODD  AND  STRUTHERS,  DES  MOINES,  IOWA 

HOLT  TRACTOR  COMPANY,  STOCKTON,  CAL. 

DUNT  MOSS  COMPANY,  BOSTON,  MASS. 


AUTHOR'S  PREFACE 

The  information  set  forth  in  this  little  vol- 
ume is  gleaned  from  the  experience  of  a  number 
of  years  spent  in  advising  and  aiding  farmers 
in  these  matters,  and  is  largely  an  outgrowth 
of  the  material  I  have  printed  in  the  Rural 
New-Yorker  in  reply  to  hundreds  of  questions 
from  its  readers  in  all  portions  of  America. 
In  a  few  cases  the  "talk"  is  based  on  articles 
contributed  by  me  to  prominent  farm  journals 
of  both  the  United  States  and  Canada,  such 
as  Hoard's  Dairyman,  The  Field  Illustrated, 
American  Cultivator,  Northwestern  Agriculturist, 
Kimball's  Dairy  Farmer,  Up-to-date  Farming, 
of  the  United  States,  and  The  Farme/s  Ad- 
vocate, The  Weekly  Sun,  The  Mail  and  Empire, 
and  the  Manitoba  Free  Press,  of  Canada.  In 
every  case,  however,  the  material  has  been 
carefully  revised  and  rewritten  and  new  illus- 
trations used.  There  has  been  no  attempt 
whatever  to  make  this  a  textbook  or  even  a 


Vlll  AUTHOR  S    PREFACE 

treatise  on  Farm  Engineering.  Its  sole  aim  is 
to  present  the  material  in  an  interesting  and 
popular  form  for  the  use  of  farmers  who  have 
neither  the  training  nor  the  inclination  to  wade 
through  more  technical  volumes  on  the  subject. 
The  list  of  topics  included  is  not  a  long  one, 
nor  does  it  by  any  means  exhaust  the  interests 
of  the  farmers.  It  is  a  selection  made  from 
the  things  most  often  inquired  about  during 
the  last  three  or  four  years  and  found  to  be 
most  perplexing  to  the  farmers. 

R.  P.  Clarkson. 


THE  FIELD  OF  FARM  ENGINEERING 

As  one  thinks  over  the  work  of  the  farmer, 
it  is  astonishing  to  note  how  much  engineering 
enters  into  it.  The  choice  of  materials  for 
buildings,  for  roads,  walks,  and  fences;  the 
erection  of  the  buildings  themselves;  the  care 
and  operation  of  machinery,  including  tractors 
and  automobiles;  the  selection  of  a  good  water 
supply  and  the  system  whereby  the  water  is 
made  available  for  domestic  purposes,  for  stock, 
and  for  crop  irrigation;  the  drainage  of  land; 
the  disposal  of  sewage;  the  installation  of  farm 
power,  possibly  by  harnessing  some  small, 
swiftly  running  stream  or  some  waterfall;  the 
industrial  use  of  crops  and  the  waste  products 
from  crops — all  this  is  engineering  work  and 
lies  rather  in  the  province  of  the  engineer  than 
in  that  of  the  agriculturist  alone. 

These  are  merely  the  general  engineering 
subjects  with  which  every  farmer  deals.  Many 
cases  arise  where  special  engineering  informa- 
tion is  of  value.     Trouble  with  the  telephone 


X  THE    FIELD    OF    FARM    ENGINEERING 

lines;  the  matter  of  lightning  protection;  the 
value  and  disposal  of  water  and  mineral  rights; 
the  utilization  of  raw  products  found  in  the 
land,  such  as  limestone,  coal,  peat,  oil,  metal 
ores,  and  similar  substances;  even  the  opera- 
tion of  the  furnace  and  the  choice  of  fuel  are 
subjects  which  receive  careful  study  in  any 
first-class  engineering  training. 

Farming  might  almost  be  defined  as  a  branch 
of  engineering  if  we  take  the  generally  accepted 
definition  that  engineering  is  the  development 
of  the  resources  of  nature  for  the  use  and  con- 
venience of  man. 


TABLE  OF  CONTENTS 

PART  I 

PAGE 

Farm  Buildings  and  Building  Materials 

Farm  Building,  Design,  and  Construction        .      .  3 

The  Farm  Icehouse 1 1 

The  Principles  of  Cold  Storage 21 

The  Waterproofing  of  Concrete 26 

Artificial  Stones  and  Composition  Flooring       .      .  36 

Paints  and  Painting 43 

Lightning  Rods  and  Rodding 47 

PART  II 

Farm  Water  Supply  and  Sewage  Disposal 

The  Sources  of  a  Pure  Water  Supply 61 

Running  Water  for  Fifteen  Dollars 68 

A  Sand  Filter  for  Rain  or  Brook  Water     ....  75 

Softening  Hard  Water 79 

The  Hydraulic  Ram  and  the  Ram-pump        ...  82 

Disposal  of  House  Sewage 89 

PART  III 

Farm  Power 

Kerosene,  Gasoline,  and  Coal  as  Fuels      ....  97 

The  Oil  Tractor  on  the  Small  Farm 102 


Xll  TABLE    OF    CONTENTS 

PAGE 

The  Ignition  System  and  Ignition  Control  of  the 

Gasoline  Engine in 

Determining  the  Horsepower  of  an  Engine  .      .      .119 

Utilizing  Small  Streams  for  Power 129 

The  Storage  Battery  for  the  Farm 145 

PART  IV 

Drainage  and  Irrigation 

The  Principles  of  Drainage 159 

Construction  of  the  Tile  Drain 172 

Some  Facts  Concerning  Small  Irrigation  Practice  178 

PART  V 

Miscellaneous  Engineering  Talks 

The  Cost  of  Road  Building 189 

The  Working  Principles  of  Orchard  Heaters     .      .  194 

The  Forms  of  Electricity 199 

PART  VI 

Useful  Tables  for  Engineering  Calculations 

I.     The  Equivalents  of  One  Horsepower      .      .   205 
II.     Absolute  Efficiency  of  Various  Engines  .      .   206 

III.  Weights  of  Various  Materials    ....   208 

IV.  Strength  of  Various  Materials    ....   212 
V.     The  Heating  Value  of  Fuels       .      .      .      .214 

VI.     Water  Heads  and  Corresponding  Pressures  216 
VII.    Water  Powers  for  Various  Heads       .      .      .217 

Index 219 


LIST  OF  ILLUSTRATIONS 

Line  Cuts  and  Half-tones 

figure  facing  pagb 

20 .     The  Caterpillar  Tractor  Adapted  for  Soft 

Soils  Particularly      ....     Frontispiece 

1 .  Relative  Lengths  of  the  Enclosed  Lines 

for  the  Three  Equal  Areas  A,  B,  and 

C— In  Text 5 

2.  Approaching    the    Round    Construction. 

Note  Driveway  at  Left  to  the  Middle 
Floor 6 

3 .  Taking  Advantage  of  the  Economy  Which 

Results  from  the  Round  Construction        7 

4.  Diagram  Showing  Ventilating  System — In 

Text 7 

5.  The  Tall,  Round  Silo  Is  Best  ....  8 

6.  An  Example  of  True  Building  Efficiency  9 

7.  Simple    Roof   Ventilators    for    Icehouse 

Construction — In  Text 18 

8.  Showing  the  Discharge  Between  Clouds 

and  the  Overflow  to  Earth  ....      48 

9.  Lightning  Protection  for  the  Roof  Ven- 

tilator— In  Text 50 

10.  The  Method  of  Bending  Barbed  Wire  to 
Form  an  Enclosing  Network  for  Light- 
ning Protection — In  Text 55 

xiii 


XIV  LIST   OF   ILLUSTRATIONS 

FIGURE  FAONG  PAGE 

1 1 .  The  Proper  Arrangement  for  the  Top  of  a 

Dug  Well — In  Text 63 

12.  A  Neat  and  Desirable  Spring  Housing  .  70 

13.  A  Simple  Running  Water  System  of  Low- 

Cost — In  Text 69 

14.  A  Simple  Pneumatic  Equipment — In  Text  .  70 

15.  Illustrating  the  Simplicity  of  the  Hot- 

water  System — In  Text 72 

16.  A  Satisfactory  Sand  Filter — In   Text.     .  77 

17.  Diagram  Showing  Parts  of  Ram  and  Ram- 

pump — In  Text 85 

18.  The  Septic  Tank — In  Text 90 

19.  A  Tractor  in  the  Lumber  Country     .     .  102 

21 .  A  Caterpillar  Tractor  Working  in  Ground 

After  Plowing 103 

22 .  A  Caterpillar  Tractor  Working  in  Swamp 

Land 106 

23 .  The  Past  and  the  Present 107 

24.  A  Severe  Test  for  Any  Machine  .     .     .  107 

25.  The  One  Man  Outfit  Plowing  ....  108 

26.  The  Engine  Indicator — In  Text.     .     .     .  121 

27.  A  Typical  Indicator  Card — In  Text     .     .  123 

28.  One  Form  of  Prony  Brake — In  Text    .     .  124 

29.  Types  of  Water-wheels — In  Text   .     .     .  133 

30.  Diagrammatic  Representation  of  Typical 

Turbine  Wheels — In  Text 138 

31.  General  Location  of  Dam  and  Turbine 

Wheel  in  Most  Installations — In  Text  140 

32.  Charging  a  Small  Storage  Battery  with 

Alternating  Current  Lighting  Circuit  146 

33.  The  Grid  Before  Pasting 147 

34.  The  Pasted  Plate  Completed    ....  147 


LIST    OF    ILLUSTRATIONS  XV 

FIGURE  FACING   PAGE 

35.  The  Plante  Plate  After  Shredding  but 

Before  "Forming"  the  Paste      .      .     .  147 

36.  The  Plante  Plate  Completed  and  "Formed"  147 

37.  The  Lead  Cell  at  the  Left.    The  Edison 

at  the  Right 150 

38.  The  Edison  Positive  Plate 151 

39.  The  Edison  Negative  Plate 151 

40.  A  Kerosene  Engine  Belted  to  a  Lighting 

Generator 154 

41 .  A  Natural  System  of  Drainage — In  Text .  167 

42.  Other  Drainage  Systems — In  Text  .     .     .  170 

43 .  An  Orchard  Heater — In  Text     ....  196 


PART  I 

FARM  BUILDINGS  AND  BUILDING 
MATERIALS 

Farm  Building,  Design,  and  Construction. 

The  Farm  Icehouse. 

The  Principles  of  Cold  Storage. 

The  Waterproofing  of  Concrete. 

Artificial  Stones  and  Composition  Flooring. 

Paints  and  Painting. 

Lightning  Rods  and  Rodding. 


PRACTICAL  TALKS  ON  FARM 
ENGINEERING 

CHAPTER    I 

Farm  Building,  Design,  and  Construction 

There  are  a  great  many  important  small 
things  which  everybody  knows  when  he  has 
leisure  to  recall  them,  but  which  do  not  always 
come  to  mind  at  just  the  time  when  they  are 
most  needed.  In  planning  for  the  future  care 
and  repair  of  the  new  farm  buildings  it  is  often 
the  little  things  that  count.  We  must  build 
not  only  with  an  eye  to  present  conditions  but 
also  keeping  in  mind  the  frequent  renewal  of 
some  part  of  the  building,  the  painting  and  up- 
keep and,  more  important  still,  the  ease  and 
convenience  with  which  we  shall  be  able  to 
work  in  the  building.  There  is  no  greater 
mistake  made  than  to  consider  a  thing  which 
makes  work  easier  as  a  luxury.  It  is  a  prime 
necessity,  because  anything  which  makes  work 

3 


4  FARM    ENGINEERING 

easier  will  make  the  worker  able  to  do  more  and 
thus  will  make  what  he  does  do  cost  less.  If 
money  is  at  hand  to  make  this  possible,  every 
possible  time  saver  should  be  employed.  Con- 
sider, for  example,  a  plan  which  would  save 
two  hours  a  week  in  the  care  of  horses  or  stock. 
That  means  one  hundred  and  four  hours  a  year 
could  be  used  in  doing  some  other  work,  and  at 
fifteen  cents  an  hour,  the  sum  of  #15.60  could 
be  earned.  This  amount  is  the  interest  on  three 
hundred  and  twelve  dollars  at  5  per  cent.  That 
is,  the  plan  which  saves  two  hours  a  week  of 
your  time  gives  you  as  much  cash  return  in  a 
year  as  would  the  sum  of  #312  invested  in  the 
bank.  Therefore  that  time-saving  plan  is  worth 
$312  to  you. 

In  planning  the  shape  of  buildings,  keep  in 
mind  that  you  wish  to  enclose  the  largest  possi- 
ble space  for  the  least  amount  of  money.  A 
round  building  will  do  this  but  a  square  build- 
ing is  a  close  second  choice.  The  most  waste- 
ful shapes  are  the  long  narrow  buildings.  For 
example,  consider  a  building  built  round  and 
77  feet  in  diameter.  The  space  enclosed  will  be 
about  4,660  square  feet  and  the  length  of  the 
wall   along   the   ground   will   be   242   feet.     A 


FARM    BUILDING    AND    DESIGN  5 

square  building  enclosing  the  same  space  will 
have  to  be  slightly  more  than  68  feet  square. 
Thus  the  wall  will  be  272  feet  long,  so  that,  if 
the  barns  are  the  same  height,  the  square  barn 
will  take  about  12  per  cent,  more  lumber  for 
building  the  walls,  and  every  time  it  is  painted 
it  will  cost  12  per  cent,  more  to  do  it.  The 
round  barn  will  be  warmer  in  winter  because 


2+2  rn 

272  Tt 


Fig.  I. — Relative  lengths  of  the  enclosing  lines  for  the  three 
equal  areas  A,  B,  and  C 

there  is  less  radiating  wall  space.  For  the 
same  reason  it  will  be  cooler  in  summer.  The 
saving  of  either  of  these  barns  over  a  long  barn 
is  very  great.  To  enclose  the  same  space  as 
these,  suppose  we  build  a  barn  n6>^  feet  long 
by  40  feet  wide.  The  wall  space  would  be  313 
feet  long  or  nearly  30  per  cent,  more  lumber  and 
paint  would  be  required  than  in  the  case  of  the 


6  FARM    ENGINEERING 

round  barn,  and  about  15  per  cent,  more  than  if 
the  square  barn  were  built.  Such  a  long  barn 
would  be  colder  in  winter  and  warmer  in  summer. 

The  round  barn  of  the  "consolidated"  type 
with  a  round  silo  in  the  centre  and  all  the  ani- 
mals and  feed  under  one  roof  is  nearest  to  the 
ideal  construction.  Less  time  and  labour  are 
required  in  caring  for  the  stock,  with  the  result 
that  better  care  is  given  them.  Make  it  a 
gravity  barn,  as  I  like  to  call  it.  That  is,  have 
a  driveway  to  the  upper  floor  so  that  hay,  grain, 
and  feed  may  be  delivered  up  there,  and  manure, 
waste,  etc.,  taken  out  at  the  bottom  floor. 
Have  all  the  movement  of  material  done  by 
gravity.  If  you  want  a  thrashing-floor,  have  it 
on  the  top  floor  where  the  wagons  can  unload 
directly.  Then  have  the  granary  on  the  floor 
below  so  that  the  grain  will  not  have  to  be  lifted. 
Put  the  stock  on  the  floor  below  this  and  have 
the  feed  go  down  to  them  through  a  chute.  If 
grain  is  to  be  shipped,  the  wagons  may  be 
loaded  at  the  lowest  floor.  In  fact,  anything 
in  the  barn  may  be  loaded  in  wagons  without 
lifting. 

A  three  floor  barn  is  by  no  means  impracti- 
cable, nor  is  it  an  impossibility  in  any  location 


FARM    BUILDING    AND    DESIGN  7 

whatever.  Such  barns  are  frequent,  but  of 
course  the  construction  of  proper  driveways  is 
much  easier  where  the  barn  can  be  built  against 
or  near  a  hillside  or  bank.  If  some  of  these 
arrangements  must  be  changed  to  fit  your  case, 
use  what  you  can,  for  the  nearer  you  come  to 
the  ideal  construction,  the  more  convenient  and 
therefore  the  more  valuable  your  barn  will  be. 


PN 


fi% 


Fig.  4. — Diagram  showing  ventilating  system.    The  grain  chutes 
may  be  utilized  in  this  manner 

Ventilation  of  farm  buildings  is  far  more  im- 
portant than  is  commonly  believed.  Proper 
ventilation  will  save  you  money  in  building,  for 
if  you  arrange  for  a  constant  and  sufficient 
supply  of  fresh  air,  the  stock  may  be  crowded 
as  close  together  as  desired.     Consequently  the 


8  FARM    ENGINEERING 

building  may  be  smaller  for  the  same  number  of 
animals.  The  best  ventilators  open  into  the 
top  of  a  room,  allowing  the  cold  air  from  outside 
to  sink  down  through  the  upper  layer  of  warm 
air.  In  this  way  the  warm  air  at  the  top  of  the 
room  is  not  wasted,  as  usually  is  the  case,  but 
is  utilized  in  warming  the  room.  The  exit  for 
the  impure  air  should  be  arranged  to  open  close 
to  the  floor,  for  that  is  where  the  impure  air  is, 
and  that  is  where  most  of  the  animals  are  breath- 
ing. If  these  matters  are  properly  attended  to, 
neither  low  ceilings  nor  ground  cellars  are  ob- 
jectionable if  the  rooms  are  dry  and  light.  Pure 
air  and  bright  sunshine  are  as  necessary  as  safe 
water  and  good  food. 

For  a  silo  nothing  but  a  round  shape  should 
be  considered  for  a  moment.  For  the  same 
cost  of  construction,  it  will  hold  more  material 
and  the  ensilage  will  pack  better.  There  will 
be  less  waste  due  to  air  exposure  or  freezing  on 
the  sides,  and  the  silo  will  be  better  able  to  with- 
stand the  enormously  heavy  strains  upon  it. 
The  side  pressure  on  the  walls  amounts  to 
slightly  over  ten  pounds  per  square  foot  of  wall 
space  for  each  foot  in  depth,  and  the  silo  must  be 
deep.     Most  of  the  early  silos  were  made  square 


i  i  I  111  I  111  IIUll 


Fig.  5- 


The  tall,  round  silo  is  best.     This  one  is  built  with 
concrete  blocks 


Fig.  6.— An  example  of  true  building  efficiency.     The  chute 
between  the  silos 


FARM   BUILDING   AND   DESIGN  9 

or  rectangular  and  shallow.  They  were  not 
successful  until  weights  were  used  to  press  the 
ensilage  tightly  into  place  and  expel  the  air. 
To-day  the  best  silos  are  built  tall  and  the  weight 
of  the  ensilage  itself  keeps  the  mass  packed 
tight.  To  do  this  the  walls  must  be  as  smooth 
as  possible.  Otherwise  the  ensilage  at  the 
sides  will  not  pack  down  and  will  spoil.  Many 
farmers  have  this  trouble,  due  entirely  to  rough 
walls,  and  the  only  remedy  is  to  tramp  the 
material  down  at  the  sides  continually  during 
filling. 

For  icehouse  construction  the  round  shape 
may  be  more  economical,  even  if  the  ice  is  packed 
in  a  square  block,  provided  the  corners  of  the 
block  are  brought  up  close  to  the  sides.  A 
much  better  plan,  however,  is  to  pack  the  ice 
into  a  block  approaching  in  shape  the  inside 
shape  of  the  icehouse.  When  this  is  done,  the 
saving  in  building  material  for  the  same  amount 
of  ice  stored  will  be  at  least  10  per  cent.  Noth- 
ing makes  a  better  icehouse  than  an  old  silo 
properly  repaired  and  the  floor  well  drained. 

There  is  another  general  plan  which  should 
be  considered  in  every  building  operation.  It  is 
to  make  every  beam  and  every  board  do  as  much 


IO  FARM    ENGINEERING 

service  as  possible.  If  there  must  be  heavy 
uprights  to  divide  the  stalls,  let  them  support 
the  next  floor.  If  you  must  build  a  partition 
for  a  box  stall,  let  it  do  double  service  by  being 
also  the  wall  of  the  harness  room.  If  you  have 
a  hay  chute  or  a  grain  chute  from  the  upper 
floor,  continue  it  on  up  to  the  roof  and  let  it  do 
duty  as  a  ventilator  for  the  lower  floors.  Plan 
to  make  the  building  ioo  per  cent,  efficient. 


CHAPTER    II 

The  Farm  Icehouse 

The  advantage  and  convenience  of  having  a 
good  supply  of  ice  is  far  beyond  the  small  cost  of 
gathering  it,  not  only  to  the  general  farmer  but 
also  to  the  dairyman,  the  country  merchant, 
and  the  rural  dweller.  Many  times  a  vacant 
shed,  a  corner  of  the  barn,  an  unused  cellar,  an 
empty  silo,  a  vegetable  storehouse,  a  dry  well, 
or  even  an  old  cistern  in  the  ground,  when 
properly  cleaned  and  fitted  up  in  accordance 
with  the  principles  here  given,  will  serve  as 
a  satisfactory  icehouse  for  many  years.  The 
successful  icehouse  is  not  necessarily  the  most 
expensive  one.  In  southern  Virginia  a  hole  dug 
in  the  ground  entirely  above  the  water  level  and 
lined  with  native  clay  held  ice  satisfactorily 
through  the  fall.  Its  only  covering  was  of  leaves 
and  pine  boughs.  This  is  the  type  used  by  the 
Romans  in  the  early  ages  to  keep  snow,  and  it  is 
now  quite  common  in  many  parts  of  this  country. 


12  FARM    ENGINEERING 

As  another  extreme  of  simple  construction,  a 
farmer  in  New  York  State  built  four  walls  of 
single  thickness  of  board  supported  by  up- 
right green  poles  freshly  cut  from  the  woods. 
He  filled  it  with  ice  surrounded  by  a  foot  of  saw- 
dust, using  a  layer  of  sawdust  for  a  floor  and 
another  layer  for  covering.  It  had  no  roof, 
doors,  nor  windows,  and  the  ice  kept  all  summer 
without  much  waste. 

It  is  obvious  from  these  two  examples  that 
building  material,  whether  wood,  earth,  stone, 
brick,  or  concrete  may  not  be  the  deciding 
factor  in  the  keeping  of  ice.  The  secret  is  in 
the  strict  observance  of  four  principles  all  of 
which  finally  reduce  to  one,  namely,  good  in- 
sulation. The  four  principles  are:  first,  there 
must  be  good  under-drainage  to  carry  off  the 
melted  ice,  for  otherwise  it  would  form  a  con- 
ductor of  heat  to  the  remainder  of  the  ice 
stored,  and  would  gradually  melt  it  from  under- 
neath. Water  melts  ice  much  faster  than  air, 
for  the  latter  merely  affects  the  surface  while 
the  former  penetrates  throughout.  Second, 
there  must  be  perfect  ventilation  at  the  top  of 
the  ice  in  order  that  the  covering  of  sawdust, 
straw,  hay,  moss,  or  leaves  may  be  kept  as  dry 


THE    FARM    ICEHOUSE  13 

as  possible  so  that  it  will  not  form  a  conductor 
for  the  heat  from  the  air  and  melt  the  ice  on  top. 
Third,  the  ice  must  be  packed  so  as  to  prevent 
the  circulation  of  air  through  the  mass,  for  there 
is  certain  to  be  some  heated  air  enter  into  the 
house  when  the  doors,  windows,  ventilators,  or 
top  are  opened.  These  currents  of  air  rapidly 
warm  up,  while  dead  air  does  not  readily  become 
heated  because  of  the  fact  that  air  is  a  very 
poor  conductor  of  heat.  Fourth,  good  insu- 
lation at  the  sides  and  bottom  must  be  care- 
fully provided. 

The  size  of  the  house  needed  may  be  deter- 
mined from  the  fact  that  a  ton  of  stored  ice 
occupies  approximately  42  cubic  feet  of  space. 
The  average  size  of  house  for  a  small  farm  is 
about  ten  feet  high  from  the  ground  to  eaves  with 
an  inside  area  12  x  14  feet.  After  allowing  for 
the  space  occupied  by  the  sawdust  around  and 
under  the  ice,  this  will  give  room  for  the  storage 
of  from  25  to  28  tons  of  ice.  A  cubic  foot  of 
solid  ice  weighs  close  to  57I  pounds,  so  that 
35  cubic  feet  of  solid  ice  would  weigh  a  ton. 
From  this  we  can  estimate  the  amount  possible 
to  cut  from  a  pond.  The  thickness  of  the  cakes 
cut  ranges  from  six  inches  in  the  central  states 


14  FARM    ENGINEERING 

to  1 6  and  even  20  inches  in  the  north.  Prob- 
ably 12  to  14  inches  is  the  average.  The  cakes 
are  cut  various  sizes  also,  perhaps  12  x  16  and 
16  x  16  are  common  sizes,  but  this  is  not  im- 
portant. Assuming  cakes  12  inches  thick  and 
12  x  16  inches,  there  will  be  26  of  them  to  the 
ton,  each  one  weighing  j6\  pounds.  In  the 
field,  allowing  for  breakage  and  waste,  a  surface 
of  50  feet  square  will  harvest  45  tons  of  12-inch 
ice. 

Having  determined  upon  the  size  of  house 
and  the  outlay  of  money  that  can  be  afforded, 
it  remains  to  determine  the  material  to  be  used 
and  the  plan  to  be  followed.  Beyond  any 
reasonable  doubt  wood  is  better  in  many  ways 
than  stone,  brick,  or  concrete  for  icehouse  con- 
struction, although  any  of  these  may  be  used  with 
satisfaction  if  the  ice  is  packed  far  from  the  walls 
and  well  insulated  from  them  by  ten  or  twelve 
inches  of  sawdust.  The  only  objection  to  wood 
which  any  one  can  have  is  its  tendency  to  rot 
under  the  continued  influence  of  moisture  inside 
and  dryness  outside.  For  this  reason  cypress 
is  to  be  highly  recommended  as  a  serviceable 
wood,  although  pine  will  last  for  some  years  and 
is  quite  generally  used  in  practice. 


THE    FARM   ICEHOUSE  1 5 

For  a  foundation  concrete  is  best,  all  things 
considered.  Let  it  go  into  the  ground  below 
the  frost  line  and  extend  a  foot  above  ground  to 
keep  the  sills  dry.  Unless  the  soil  is  well 
drained,  there  should  be  a  main  ditch  with  side 
branches  cut  in  the  floor,  covering  the  whole 
space  below  the  ice,  the  main  ditch  leading  out 
on  the  lower  side.  Fill  the  ditches  with  broken 
stone,  crockery,  brick,  or  clinkers,  and  spread  a 
thin  layer  over  the  whole  floor.  On  top  of  the 
stone  place  a  layer  of  straw  covered  with  a 
thickness  of  coal  ashes.  On  top  of  the  ashes 
floor  boards  may  be  placed  with  cracks  between 
them  to  allow  free  drainage  of  the  water  from  the 
melted  ice.  More  often,  however,  the  boards 
are  dispensed  with  and  an  eight  or  ten  inch 
layer  of  sawdust  put  directly  on  the  ashes,  the 
ice  being  packed  on  that. 

The  walls  may  be  either  single  or  double,  but 
should  be  built  with  matched  boards  or  papered 
with  tar  roofing  paper.  I  should  recommend 
both.  The  paper  is  cheap,  costing  $1.50  to  $2 
for  a  500-foot  roll,  so  it  does  not  add  much  to 
the  cost  of  the  work,  but  it  does  give  a  much 
better  house.  If  the  single  walls  are  papered 
it  should  be  done  on  the  outside,  of  course, 


l6  FARM    ENGINEERING 

while  if  the  building  is  made  with  double  walls, 
the  papering  should  be  on  the  sides  within  the 
air  space.  Double  walls  are  much  better  for  in- 
sulation and  may  be  easily  provided  by  nailing 
the  boards  on  both  sides  of  the  2x4  joists  used 
as  uprights.  This  leaves  a  four-inch  dead  air 
space  between  the  walls  which  should  not  be 
filled  with  sawdust  nor  with  anything  else. 
The  best  insulator  we  have  is  dead  air,  and  the 
purpose  of  sawdust,  felt,  wool,  shavings,  and 
such  substances  is  merely  to  keep  the  air  dead 
— that  is,  these  substances  prevent  circulation 
of  air  by  catching  small  quantities  in  the  spaces 
between  the  particles.  The  use  of  these  sub- 
stances is  not  to  be  recommended  either  in 
icehouses  between  walls  or  in  the  walls  of  cold- 
storage  boxes.  In  either  case  the  filling  would 
become  damp  and  remain  so,  thus  rotting  the 
construction  from  the  inside.  In  cold-storage 
boxes  it  also  will  absorb  and  retain  the  odours, 
making  the  box  unfit  for  keeping  eatable  prod- 
uce. Furthermore,  when  damp  such  fillings  are 
reasonably  good  heat  conductors. 

In  the  air  space  between  the  boards,  in  the 
icehouse  construction,  every  three  or  four  feet 
up  there  should  be  a  strip  of  tarred  paper  tacked 


THE    FARM    ICEHOUSE  IJ 

to  form  a  horizontal  partition,  thus  preventing 
any  up  and  down  circulation  of  the  air.  The 
result  of  this  construction  is  that  the  ice  is 
surrounded  by  walls  consisting  of  a  large  num- 
ber of  boxes  containing  dead  air.  These  boxes 
will  be  from  three  to  four  feet  square  and  four 
inches  thick  (the  thickness  of  the  air  space). 

The  sills  of  the  house  should  be  laid  directly 
on  the  concrete  foundation  and  in  close  union 
with  the  concrete  to  prevent  entrance  of  the  air 
between  them.  In  my  experience  it  has  been 
found  well  to  lay  a  coating  of  tar  or  asphalt  on 
the  foundation  walls  and  on  this  put  the  sills, 
thus  making  an  air-tight  job.  There  must  be 
no  entrance  of  air  underneath  the  ice.  It  is 
true  that  a  small  amount  will  enter  through  the 
drain  if  the  latter  is  not  trapped,  but  this  is  not 
sufficient  to  do  any  harm.  In  a  commercial 
house  of  large  size,  however,  the  drain  should  be 
of  tile  and  trapped  as  it  comes  from  under  the 
icehouse.  Preferably,  too,  there  is  a  drain 
around  the  foundation  on  the  outside,  both  of 
the  drains  being  brought  together  and  led  away 
to  a  lower  level. 

The  roof  for  a  small  building  may  be  almost 
anything  to  shed  the  rain,  keep  off  the  sun,  and 


1 8  FARM    ENGINEERING 

provide  good  ventilation.  The  latter  feature 
is  the  one  most  important  point  in  connec- 
tion with  building  the  house.  The  ventilators 
should  be  closeable  and  kept  closed  on  foggy 
days  and  nights.  For  this  reason  trap-doors 
on  the  sides  and  roof  are  preferable.  The  roof 
thould  be  a  V-shaped  or  hipped  roof,  with  trap- 


Fig.  7. — Simple  roof  ventilators  for  icehouse  construction. 
This  view  shows  a  trap-door  arrangement  for  the  end  walls, 
giving  opportunity  for  proper  ventilation 

doors  at  each  end  and  at  the  ridge.  Near  the 
top  of  each  end  wall  arrange  a  small  door.  Each 
fine,  dry  day  open  one  of  these  doors  and  the 
opposite  trap  so  that  the  air  may  circulate  freely 
and  keep  the  top  dressing  or  covering  of  saw- 
dust dry.  This  top  dressing  should  not  be  too 
thick,  the  practice  being  to  have  it  from  eight  to 
twelve  inches.     The  dressing  must  be  looked 


THE    FARM   ICEHOUSE  19 

after  and  kept  dry  at  any  cost.  It  will  be 
found  helpful,  although  a  nuisance,  to  divide 
the  top  layer  by  a  thick  layer  of  newspaper. 

In  packing,  the  first  layer  is  commonly  placed 
on  edge  rather  than  being  laid  flat.  There 
is  no  less  wasting  that  way,  for,  although  each 
cake  wastes  less,  there  are  more  cakes  on 
the  floor.  Sometimes  this  plan  is  followed 
throughout,  the  advantage  being  that  in  break- 
ing the  ice  out  there  is  less  adhering  surface 
between  the  cakes.  It  is  harder  to  pack  this 
way,  however,  and  the  liability  to  undue  side- 
wall  pressure  is  greater.  At  least  every  third 
layer,  no  matter  how  packed,  should  be  laid  so 
as  to  break  the  joints  of  the  previous  layer  that 
there  may  be  no  circulation  through  the  mass. 
The  packing  can  be  done  up  to  within  six  inches 
of  the  side  walls  if  a  double  wall  is  used,  and  up 
to  within  eight  or  ten  inches  if  a  single  wood 
side.  As  stated  before,  if  concrete,  stone,  or 
brick  is  used,  there  should  be  from  ten  to  twelve 
inches  left  around  the  sides.  In  every  case  the 
space  left  should  be  filled  with  sawdust  lightly 
tamped  into  place  but  not  rammed  tightly. 
Hard  tamping  forces  the  sawdust  down  so 
solidly  as  to  remove  most  of  the  air,  while  light 


20  FARM    ENGINEERING 

tamping  keeps  the  mass  porous  but  yet  held  to- 
gether tightly  enough  to  retain  the  air  and  pre- 
vent its  escape  or  circulation. 

In  conclusion,  it  should  be  said  that  the  cakes 
must  be  cut  as  true  as  possible,  and  no  small 
pieces  or  broken  cakes  should  be  allowed  to 
enter  the  house.  The  ice  should  be  packed  in 
freezing  weather  so  that  the  cakes  will  be  dry 
and  not  freeze  together  in  the  house.  Each 
cake  should  be  kept  an  inch  or  an  inch  and  a 
half  from  its  neighbour  on  every  side. 


CHAPTER    III 
The  Principles  of  Cold  Storage 

Most  progressive  farmers  have  learned  the 
value  of  the  individual  icehouse,  yet  have  not 
realized  that  the  most  economical  way  of  using 
the  ice  cannot  be  developed  without  a  prop- 
erly constructed  cold-storage  chamber.  Cream- 
ery and  cooperative  cold-storage  chambers  are 
getting  to  be  quite  common  now,  and  their  im- 
portance is  realized.  As  the  farmer  observes 
them  in  use  he  will  undoubtedly  come  to 
appreciate  the  value  to  him  of  a  similar  house 
built  on  a  smaller  scale. 

The  details  of  construction  may,  as  in  the 
case  of  the  icehouse,  be  widely  varied  to  suit 
particular  needs.  There  are  certain  fundamen- 
tal principles  which  can  be  laid  down  for  guid- 
ance, however,  and  close  adherence  to  them 
will  mean  success  in  the  construction.  Satis- 
factory insulation  can  only  be  obtained  through 
the  use  of  double  walls  for  the  chamber,  in  this 


22  FARM    ENGINEERING 

way  providing  a  dead  air  space  between  the 
walls,  as  that  is  the  best  form  of  protection. 
The  air  within  the  space  must  be  dead  air  so 
the  walls  must  be  airtight  to  give  satisfaction. 
There  are  many  other  ways  of  insulating,  as  by 
filling  the  space  between  walls  with  some  so- 
called  "non-conducting"  substances  such  as 
the  following  named  in  the  order  of  their  desir- 
ability: hair  felt,  slag  wool,  wood  ashes,  chopped 
straw,  charcoal,  cork,  and  others.  The  insulat- 
ing properties  of  these  substances  are  largely 
owing  to  the  fact  that  they  enclose  in  the  tiny 
spaces  between  the  individual  particles  small 
amounts  of  dead  air  which  cannot  escape. 
That  air  is  the  insulator.  For  this  reason  the 
substances  cannot  be  packed  solid,  and  should 
be  lightly  tamped  into  place  rather  than  rammed 
hard.  For  cold-storage  work  it  should  be  borne 
in  mind  that  something  must  be  chosen  which 
does  not  readily  absorb  moisture  and  odours. 
There  is  no  one  substance  which  does  not  do 
this  to  some  extent.  If  the  building  can  be 
built  with  matched  boards  and  the  dead  air 
space  lined  with  tarred  paper,  the  space  need 
not  be  filled  with  anything.  In  fact,  a  filling 
would  be  a  decided  detriment. 


THE    PRINCIPLES    OF    COLD    STORAGE  23 

Moisture  has  the  property  of  absorbing  many 
gases  and  impurities  from  the  stores,  so  it  is  very 
desirable  that  the  air  in  the  chamber  be  kept  as 
dry  as  possible  and  that  the  moisture  which  it 
does  take  up  be  removed.  In  this  way  the 
air  may  be  purified.  The  way  in  which  it  is 
accomplished  is  by  providing  proper  circulation 
of  the  air  in  the  storage  chamber  and  thus  cool- 
ing the  stores  by  circulation  of  the  cold  air  in 
contact  with  them  rather  than  by  radiation.  Un- 
less cooling  is  done  in  this  way  the  moisture 
which  the  air  contains  will  be  deposited  on  the 
stores  and  not  on  the  ice.  This,  of  course,  will 
cause  some  of  the  packed  material  to  become 
tainted. 

To  get  a  good  circulation  it  is  necessary  to 
appreciate  the  fact  that  cold  air  drops  and  warm 
air  rises.  All  that  needs  to  be  looked  out  for 
then  is  to  have  the  ice  box  above  the  level  of  the 
storage  space  floor  and  to  introduce  the  cold  air 
at  the  bottom  of  the  storage  space,  providing 
an  outlet  and  return  at  the  top  of  the  chamber 
for  the  heated  air  to  go  back  to  be  cooled  and 
deprived  of  its  moisture.  For  a  small  chamber 
it  will  be  satisfactory  if  the  cold  air  is  allowed  to 
enter  all  along  the  lower  edge  and  the  warm  air 


24  FARM    ENGINEERING 

taken  out  the  upper  and  diagonally  opposite 
edge.  This  will  make  it  necessary  for  the  air 
to  cross  and  circulate  all  through  the  storage 
space  before  reaching  the  outlet.  In  a  larger 
chamber  the  cold  air  could  be  introduced  at  the 
centre  of  the  floor  and  taken  out  at  each  of  the 
upper  side  edges.  In  a  still  larger  room  the  cold 
air  may  be  introduced  along  two  side  edges  at  the 
bottom  and  allowed  to  go  out  through  two  side 
edges  at  the  top.  Shields  or  deflectors,  which 
maybe  made  of  wood  painted  with  enamel,  should 
be  placed  so  as  to  prevent  the  cold  air  as  it  warms 
up  going  from  the  inlet  opening  directly  to  the 
outlet  opening  without  circulating  through  the 
room.  These  deflectors  should  slope  from  the 
bottom  up  and  be  placed  just  over  the  cold-air 
inlets  so  that  as  the  cold  air  warms  it  will  rise 
along  the  deflector  toward  the  outlet.  Care 
must  be  taken  not  to  place  the  deflectors  so 
as  to  pocket  any  warm  air — that  is,  do  not 
make  them  so  that  any  body  of  warm  air  will  be 
caught  in  an  upper  corner  and  have  to  go  down- 
ward to  escape.  Deflectors  are  only  necessary 
where  the  outlet  is  nearly  over  the  inlet  and  a 
path  from  one  to  the  other  does  not  lead  through 
or  near  the  centre  of  the  storage  space. 


THE  PRINCIPLES  OF  COLD  STORAGE    25 

Ventilation  is  essential,  but,  except  in  very 
large  rooms,  it  is  satisfactorily  taken  care  of  by 
the  opening  and  closing  of  the  entrance  door. 

The  packing  of  stores  in  cold  storage  is  a 
science  in  itself  and  can  only  be  taught  by  ex- 
perience. The  general  rule  is  of  value,  however, 
and  will  take  care  of  most  difficulties.  It  is  to 
pack  the  stores  fairly  close  together  and  leave 
a  space  between  them  and  the  walls  so  as  to 
allow  a  path  for  the  circulating  air.  Never 
pack  up  close  to  the  walls. 


CHAPTER    IV 

The  Waterproofing  of  Concrete 

Concrete  needs  no  waterproofing  if  it  is 
properly  mixed  and  laid.  Water  leaks  through 
because  the  mass  is  porous.  If  we  consider  the 
materials  entering  into  concrete  construction 
and  the  theory  upon  which  the  structure  is  based 
this  fact  will  become  clear  to  us.  Concrete  con- 
tains cement,  sand,  and  stone.  The  stone,  if 
used  alone,  is  extremely  porous,  for  the  spaces 
between  the  individual  stones  are  quite  marked. 
The  theory  is  that  the  sand  used  goes  to  fill 
these  spaces.  Yet  even  then  there  are  spaces 
between  the  sand  grains  and  water  will  pass 
quite  readily.  These  spaces,  however,  are  filled 
with  the  cement,  the  particles  of  which  are  so 
very  much  smaller  than  the  grains  of  sand. 
The  cement  particles  do  more  than  merely  fill 
the  spaces  between  the  sand  grains.  They  cover 
the  individual  grains  and  cement  them  together, 
embedding  the  stones  within  the  whole  mass. 

26 


THE  WATERPROOFING  OF  CONCRETE    2J 

It  is  apparent  that  if  all  the  spaces  are  filled 
water  cannot  leak  through,  while  if  the  mass  is 
filled  with  tiny  pores  not  only  will  water  pass 
through  but  these  pores  or  tubes  will  suck  up  or 
absorb  water  from  the  ground  and  from  the 
moisture  which  condenses  from  the  atmosphere. 
Such  will  be  the  case  if  the  concrete  is  "poor" 
or  "lean" — that  is,  if  it  does  not  contain  the 
proper  proportions  of  materials  or  the  proper 
sizes  of  particles  to  enable  the  cement  to 
thoroughly  unite  the  ingredients.  Cement  is 
the  costly  part  of  the  concrete  and  the  temp- 
tation is  to  use  as  little  of  it  as  possible.  This 
does  not  pay  in  building  any  foundation  walls, 
cisterns,  tanks,  and  such  structures  where  it  is 
necessary  to  prevent  the  flow  of  water  through 
the  walls.  If  the  wall  does  leak,  there  are  but 
two  things  to  do  in  order  to  remedy  the  defect: 
Either  the  pores  must  be  plugged  up  with  some 
substance  which  is  not  porous  to  water,  which 
is  not  dissolved  by  water,  which  may  be  easily 
and  cheaply  applied,  and  which  will  not  chemi- 
cally attack  the  concrete,  or  a  separate  layer 
of  waterproof  material  must  be  laid  against 
the  surface  of  the  concrete,  using  the  con- 
crete merely  for  its  mechanical  strength    and 


28  FARM    ENGINEERING 

trusting  entirely  to  this  auxiliary  layer  to  repel 
water. 

It  is  perhaps  obvious  that  in  every  case 
where  it  is  possible  to  do  so  the  waterproofing 
materials  or  layers  should  be  applied  to  the  con- 
crete on  the  side  next  to  the  water.  Unless 
this  is  done,  the  concrete  will  always  contain 
water  and  the  waterproofing  will  simply  pre- 
vent the  water  from  flowing  out.  Under  these 
conditions  neither  the  waterproofing  nor  the 
concrete  is  apt  to  give  entirely  satisfactory 
service.  The  construction  of  waterproof  con- 
crete needs  carefulness  and  thorough  work- 
manship, but  when  we  consider  the  difficulty  of 
making  a  real,  lasting  job  of  waterproofing, 
after  a  wall  has  commenced  to  leak,  it  will  be 
seen  that  care  in  the  mixing  and  laying  is  more 
than  repaid.  There  are  several  good  water- 
proofing proportions  differing  but  slightly. 
The  1-2-4  mixture  is  most  commonly  used. 
This  means  one.  part  of  cement,  two  parts  of 
sand,  and  four  parts  of  gravel  or  broken  stone. 
With  these  proportions,  one  bag  of  cement 
mixed  with  the  proper  amounts  of  sand  and 
gravel  will  give  a  bulk  of  finished  concrete  meas- 
uring about  four  cubic  feet. 


THE  WATERPROOFING  OF  CONCRETE    29 

Portland  cement  should  be  used  for  all  work 
of  this  kind.     It  may  be  purchased  ready  for 
use  in  either  bags  or  barrels,  but  the  bags  are  far 
more  convenient  for  handling.     The  sand  and 
stone  may  be  obtained  anywhere.     It  is  im- 
portant, however,  to  have  them  clean,  with  no 
mud  or  sediment  clinging  to  them  or  mixed  with 
them.     To  be  sure  of  this  they  may  be  piled  on 
a    sloping    board     platform     and    thoroughly 
drenched  with  water,  turning  them  over  several 
times  in  order  to  clean  the  bottom  and  interior 
layers.     The  sand  must  be  coarse  or  a  mixture 
of  coarse   and   fine   for  the   most   economical 
results.     The  total  spaces  between  the  particles 
of  fine  sand  are  more  and  the  total  surface  of 
the  sand  particles  which  the  cement  must  coat 
is  greater  with  fine  sand.      Hence,  the  finer  the 
the  sand  the  more  cement  must  be  used  and  the 
more   expensive   the   concrete.      Coarse   sand, 
with  a  small  amount  of  fine  sand  mixed  in,  is 
desirable,  for  the  fine  sand  fills  up  some  of  the 
spaces  between  the  coarse  particles  and  makes 
a  more  solid  concrete.     It  will  always  pay  to 
buy  coarse  sand  rather  than  use  fine  sand  which 
is   free.     The    appreciable   saving   in    concrete 
will  be  great. 


30  FARM    ENGINEERING 

Contrary  to  the  prevalent  idea,  gravel  makes 
a  better  concrete  than  broken  stone.  It  is 
more  dense  and  it  is  stronger  after  it  has  aged. 
Particularly  is  this  true  of  a  gravel  of  quartz 
pebbles. 

The  concrete  should  be  mixed  a  little  wetter 
than  is  ordinarily  done,  and  the  mixing  must  be 
thorough  in  order  that  the  proportions  may  be 
properly  intermingled.  In  laying,  great  care 
must  be  exercised  not  to  separate  out  the  in- 
gredients by  pouring  or  dropping  from  a  bucket 
or  barrow  through  a  considerable  height.  If  this 
is  done,  the  job  will  be  spoiled.  After  laying,  the 
concrete  should  be  tamped  slightly  in  order  to 
drive  out  the  air  and  fill  the  voids  or  holes. 
Following  this,  the  surface  layers  should  be 
spaded.  That  is,  a  spade  is  placed  in  between 
the  wall  and  the  form  and  drawn  up  and  down 
in  order  to  slightly  "puddle"  the  surface, 
driving  back  the  gravel  a  little  and  leaving  the 
surface  with  a  grout  as  nearly  airless  and  non- 
porous  as  possible. 

By  following  the  suggestions  given,  the  con- 
crete cannot  be  penetrated  by  water,  but  con- 
crete that  will  not  absorb  moisture  to  some 
extent  cannot  be  made.     It  is  only  possible  to 


THE  WATERPROOFING  OF  CONCRETE    3 1 

prevent  absorption  by  adding  some  waterproof- 
ing compound  to  the  concrete  when  mixing,  or 
by  treating  the  surface  of  the  concrete  after  it 
is  laid.  The  mixture  laid  under  the  above  con- 
ditions is  dense  and  close  grained  due  to  the 
excess  of  cement,  and  it  is  without  air  bubbles 
because  of  the  excess  water.  It  is  filled  with 
very  tiny  capillary  tubes  which  will  not  allow 
the  passage  of  water  yet  will  absorb  it  in  small 
quantities.  This  is  undesirable  in  many  places 
where  concrete  is  used,  and  to  prevent  it  some 
one  of  the  following  methods  are  employed. 

If  it  is  old  work  which  is  to  be  protected, 
only  surface  coatings  can  be  used,  and  their 
object  is  a  filling  of  the  pores  spoken  about. 
Four  substances  are  commonly  used  for  this, 
namely:  neat  cement,  asphalt,  paraffin,  and 
an  alum-soap  compound.  This  last  is  known 
as  the  Sylvester  treatment,  and  is  one  of  the  most 
effective.  In  a  different  form  it  is  used  also  for 
new  work  as  will  be  explained  later.  For  sur- 
face coating  a  hot  castile  soap  solution  is  made 
by  dissolving  three  quarters  of  a  pound  of  the 
soap  in  one  gallon  of  hot  water.  An  alum 
solution,  of  one  half  a  pound  of  alum  to  four 
gallons  of  water,  is  then  prepared.     The  sub- 


32  FARM    ENGINEERING 

stances  are  thoroughly  dissolved  and  alternately 
applied  to  the  wall,  the  latter  being  perfectly 
dry.  The  hot  soap  solution  is  first  applied,  a 
flat  brush  being  used  and  care  being  taken  to 
avoid  bubbles  covering  the  work.  After  this 
coat  dries  for  twenty-four  hours,  a  coating  of 
the  alum  water  is  put  on  and  allowed  to  dry  for 
a  similar  length  of  time.  In  this  way,  alternate 
coatings  to  the  extent  desired  may  be  used,  allow- 
ing a  full  day  to  elapse  between  the  coatings. 
There  is  a  chemical  process  which  takes  place 
between  the  substances  used,  the  resulting  com- 
pound plugging  up  the  pores  in  the  cement. 
The  cost  of  this  process  for  two  coatings  of  each 
material  will  be  from  35  to  40  cents  per  square 
yard. 

Paraffin,  although  rather  expensive,  is  often 
used  for  small  jobs.  It  may  be  melted  and 
applied  while  hot,  the  walls  also  being  slightly 
warmed,  or  it  may  be  dissolved  in  some  solvent 
such  as  benzol,  xylol,  or  even  benzine  of  the 
common  kind,  these  liquids  quickly  evaporat- 
ing. Several  coatings  will  be  needed,  and  each 
coating  will  cost  in  the  neighbourhood  of  50 
cents  per  square  yard.  If  you  do  the  work 
yourself  and  do  not  count  the  cost  of  your  own 


THE  WATERPROOFING  OF  CONCRETE    33 

time  and  labour,  this  cost  will  be  materially 
reduced. 

Asphalt  and  other  bituminous  products  are 
the  easiest  to  handle  and  the  surest  of  results 
in  unskilled  hands.  They  are  applied  as  liquids, 
allowed  to  dry,  and  further  coatings  given. 
Probably  the  cost  for  two  coats  will  not  exceed 
25  cents  per  square  yard. 

Cement  grout  is  a  mixture  of  cement,  sand, 
and  water  or  just  cement  and  water,  very 
liquid  and  applied  like  paint.  It  is  not  very 
efficient  when  used  on  old  concrete,  for  it 
readily  peels  or  cakes  off  after  a  short  time. 
For  a  temporary  repair  this  or  a  mixture  of 
the  same  substances  just  plastic  enough  to 
handle  with  a  trowel  is  the  most  universally 
used. 

The  surface  coatings  spoken  of  are  as  valuable 
for  concrete  blocks,  brickwork,  and  porous 
stone  as  for  straight  concrete  work.  Good 
brick  needs  very  little  attention,  although  it 
will  absorb  from  3  to  5  per  cent,  of  its  weight  of 
water,  but  such  brick  is  expensive  and  seldom 
met  with  on  the  farm.  The  common  brick  used 
will  often  absorb  from  15  to  25  per  cent,  of  its 
weight  in  water.     Concrete  blocks,  especially  if 


34  FARM   ENGINEERING 

made  by  the  continually  tamping  process  known 
as  the  dry  process,  are  extremely  porous. 

While  the  above  coatings  appear  to  be  satis- 
factory for  simple  work,  in  large  structures 
such  as  dams,  reservoirs,  and  sewers  much 
more  care  must  be  taken.  Strong  layers  are 
used  because  of  the  heavy  water  pressure 
against  them.  Felt  or  burlap  saturated  with 
tar  or  pitch,  rolled  in  a  continuous  layer  against 
the  wall  and  held  there,  is  not  only  a  satisfactory 
water  retainer  but  also  prevents  the  leakage  of 
foul  gases  which  chemically  attack  the  con- 
crete. A  method  known  as  the  integral  process 
is  practised  where  it  would  be  too  expensive  to 
use  the  thorough  workmanship  described  in 
the  early  part  of  this  article.  This  consists  in 
the  addition  to  the  cement,  when  mixed,  of  some 
fine,  dry  powder  consisting  of  extremely  small 
particles,  usually  alum  and  lime.  These,  because 
of  their  size,  may  fill  in  the  spaces  between  the 
cement  and  sand  grains  and  make  the  whole 
structure  more  dense.  Usually  only  the  cement 
which  lies  near  the  surface  is  thus  treated.  Still 
another  treatment  is  to  add  some  soap  or  oil 
emulsion  to  the  mixture.  This  forms  a  jelly 
within  the  concrete  and  fills  the  pores. 


THE  WATERPROOFING  OF  CONCRETE    35 

Lastly,  the  well-known  Sylvester  process 
before  mentioned  is  used.  Alum  is  added  to 
the  cement  and  castile  soap  is  added  to  the 
water  with  which  the  mixture  is  made.  Chem- 
ical action  then  goes  on  in  the  mass,  forming  a 
compound  which,  as  before,  fills  the  spaces. 
Many,  many  other  substances  may  be  used.  In 
fact,  one  farmer  in  waterproofing  a  cracked 
wall  filled  the  cracks  with  corn  stalk  pith  and 
wet  it,  causing  it  to  swell  and  fill  the  cracks  com- 
pletely. The  whole  object  of  waterproofing  is 
to  fill  all  holes,  pores,  and  cracks.  Any  method 
of  doing  this  satisfactorily  is  entitled  to  con- 
sideration. 


CHAPTER   V 

Artificial  Stones  and  Composition 
Flooring 

There  are  a  number  of  artificial  stones  on 
the  market  which  may  be  readily  used  by  any 
one.  They  may  be  used  in  blocks,  as  concrete 
blocks  are  used,  or  as  a  covering  for  making  a 
structure  either  fireproof  or  waterproof.  The 
latter  is  perhaps  of  most  interest  to  farmers. 
Often  it  is  desired  to  cover  old  floors  or,  with 
the  installation  of  bathroom  fixtures  in  the 
house,  it  is  desirable  to  make  a  waterproof  floor. 
For  this  latter  purpose  the  various  modifi- 
cations of  Sorel  stone  are  highly  recommended. 
Its  strength  and  hardness  exceed  that  of  any 
other  yet  produced,  and  it  is  one  of  the  cheapest 
of  the  artificial  stones.  For  stable  and  stall 
floors  it  is  also  of  considerable  value,  for  it  is 
sanitary,  easy  to  clean,  and  wears  well. 

There  are  almost  as  many  different  vari- 
eties as  there  are  users  of  the  stone,  for  every  one 

36 


ARTIFICIAL    STONES    AND    FLOORING  37 

makes  some  little  change  in  the  details  of  mix- 
ing. The  fundamental  thing  is  to  mix  in  with 
the  various  filling  substances  an  "oxychloride 
binder"  which  is  nothing  more  nor  less  than  a 
solution  of  magnesium  oxides  and  chlorides. 
This  is  used  to  moisten  the  filling  substances  in 
the  same  way  as  water  is  used  in  concrete  work. 
The  fillers  here  may  be  almost  anything— 
shredded  wood  or  cloth,  sawdust,  asbestos,  sand, 
ashes,  pebbles,  etc.  You  may  buy  the  material 
all  ready  for  use  from  any  large  paint  shop  or 
hardware  store  and  do  the  work  yourself,  or  you 
can  get  any  of  the  companies  selling  the  sub- 
stances to  do  the  work  for  you.  You  may,  if 
you  like,  mix  up  the  ingredients  and  make  your 
own  stone. 

If  you  buy  the  material  ready  to  use,  you 
will  get  two  packages.  With  one  kind  the 
packages  contain  powders  which  must  be  mixed 
together  and  water  then  added.  With  the  other 
kinds  of  composition  one  powder  and  one  liquid 
is  purchased  and  the  two  mixed.  The  mixture 
is  made  somewhat  stiffer  or  thicker  than  ordi- 
nary cement  and  is  spread  on  the  old  floor,  or  on 
the  flooring  built  to  receive  it,  to  a  depth  of 
half  an  inch.     The  surfacing  must  be  well  done 


38  FARM    ENGINEERING 

and  not  left  rough.  It  will  "set"  overnight  and 
will  be  hard  enough  then  to  walk  on  if  care  is 
observed,  but  the  floor  should  not  be  used  for 
three  or  four  days.  Probably  several  months 
will  elapse  before  the  floor  reaches  an  even 
colour  all  over.  From  time  to  time  it  will  be 
necessary  to  remove  the  white  blotches  by 
simply  washing,  the  spots  being  caused  by  the 
chemical  action  going  on  in  the  floor  material. 
After  a  time  the  floor  will  be  stone  hard  and,  of 
course,  will  be  fireproof  and  waterproof.  This 
is  a  valuable  characteristic,  for  almost  all  arti- 
ficial stone  in  common  with  brick  and  concrete 
is  very  porous  and  open  to  the  absorption  of 
water.  Composition  floorings,  however,  are  not 
open  to  this  serious  objection.  Any  desired 
colour  may  be  added  to  the  composition,  the 
earth  colours  giving  the  best  results. 

Although  this  flooring  has  but  just  been 
receiving  the  attention  of  private  builders,  it 
is  not  a  new  thing.  There  are  hundreds  of 
patents  for  different  mixtures,  and  one  kind  or 
another  has  been  used  on  the  floors  of  railroad 
cars,  in  public  buildings,  and  similar  places  for 
at  least  twenty  years.  Recently  some  of  the 
important  patents  expired,  and  during  the  past 


ARTIFICIAL    STONES   AND    FLOORING  39 

ten  years  as  many  as  fifty  companies  manu- 
facturing composition  have  come  into  existence. 
Specifically,  the  ingredients  of  one  of  the  best 
compositions  are  as  follows : 

50  parts  (by  weight)  of  calcined  (burned)  mag- 

nesite. 
15  parts  of  dolomite  (marble  dust). 

5  parts  asbestos  (shredded). 
15  parts  sawdust. 

2\  parts  silicate  of  magnesium. 
11  parts  of  earth  colours. 

Mix  the  above  powder  very  thoroughly  and 
add  the  following  liquid  until  the  proper  con- 
sistency is  obtained.  Frequently,  to  make  a 
better  union  of  the  elements,  the  above  powder 
is  added  to  \\  parts  of  muriate  of  ammonia. 

The  liquid:  equal  parts  of  water  and  chloride 
of  magnesia  solution. 

In  another  composition  flooring  the  materials 
are  mixed  at  the  shipping  point  and  the  receiver 
adds  water  and  burned  or  calcined  magnesite. 
In  this  the  specific  materials  are: 


4-0  FARM    ENGINEERING 

85  parts  magnesium  chloride  solution. 

36  parts  of  any  filler  such  as  sawdust,  ashes, 

etc. 
25  parts  of  infusorial  earth  or  fossil  flour. 

Add  to  the  above: 

100  parts  of  pulverized  burnt  magnesite. 
43^  parts  of  water. 

Desired  colouring  material  as  red  oxide  ochre, 
etc. 

All  of  these  substances  are  cheap.  The  mix- 
tures as  retailed  by  manufacturers  are  about 
fifteen  cents  per  square  foot  of  floor  surface  for 
the  substance  and  an  equal  amount  for  doing 
the  work.  Unless  you  are  willing  to  take  great 
pains  with  the  laying  and  finishing  of  the  floor, 
an  expert  should  be  allowed  to  do  it. 

By  using  the  above  mixture  but  substituting 
large  pebbles  or  stones  for  part  of  the  filling 
material  suggested,  a  first-class  concrete  is 
obtained.  The  same  mixture,  also  omitting  the 
filling  material  and  colouring  matter,  and  add- 
ing the  proper  sand  or  sharp,  small  stones,  may 
be  used  for  the  formation  of  grindstones,  emery 
wheels,  etc. 


ARTIFICIAL    STONES    AND    FLOORING  41 

Another  common  artificial  stone  used  for 
blocks  and  slabs  is  known  by  the  name  of  Ran- 
some  stone.  It  is  formed  by  mixing  sand  and 
the  silicate  of  soda  in  the  proportions  of  a  bushel 
of  sand  to  a  gallon  of  the  silicate.  The  mixture 
is  now  very  easily  worked  and  is  rammed  into 
molds  for  blocks  or  ornamental  shapes,  or  may 
even  be  rolled  into  slabs  for  walks,  paths,  and 
such  purposes.  The  slabs  or  blocks  may  then 
be  cut  in  any  desired  way.  After  being  made 
in  just  the  shape  and  size  desired,  they  are  im- 
mersed in  a  hot  solution  of  calcium  chloride 
which  is  under  pressure  so  as  to  force  it  through 
the  pores.  The  chemical  action  between  the 
sand,  the  silicate  of  soda,  and  the  calcium 
chloride  forms  a  hard  and  non-porous  cement- 
ing substance  in  the  spaces  between  the  sand 
particles,  while  some  sodium  chloride  is  formed 
in  the  process  and  must  be  washed  out  by 
thoroughly  drenching  the  blocks  or  slabs  with 
cold  water.  The  sand  enters  into  the  action 
but  slightly,  and  any  gravel  or  broken  stone  of 
small  size  may  be  mixed  in. 

The  "  Beton-Coignet "  artificial  stone  is  still 
commonly  used  because  of  its  quick  setting 
property,   its   strength,   and   its   ease  of  man- 


42  FARM    ENGINEERING 

ufacture.  The  ingredients  in  the  proportions 
of 

4  parts  lime, 

i  to  2  parts  hydraulic  cement, 
20  parts  sand 

are  very  thoroughly  mixed  by  hand.  In  this 
great  care  must  be  taken  to  insure  thorough 
mixing.  The  mass  is  then  again  mixed  in  a 
mixing  mill  of  any  kind  with  a  very,  very  little 
clean  water,  just  enough  to  moisten  the  sub- 
stances slightly.  Molds  can  then  be  rammed 
full  of  the  mixture  just  as  is  the  practice  with 
concrete.  The  finished  stone  occupies  slightly 
more  than  one  half  the  bulk  of  the  dry  mixture, 
and  weighs  practically  the  same  amount  as 
Portland  cement  concrete — that  is,  140  pounds 
per  cubic  foot. 


CHAPTER   VI 

Paints  and  Painting 

The  coming  of  spring  should  be  a  signal  for 
painting  everything  that  needs  it,  whether 
house,  barn,  fence,  or  machinery.  Particu- 
larly should  machinery  be  looked  after,  and  em- 
phasis cannot  be  too  strongly  laid  on  this  point, 
for  few  things  are  so  neglected  as  machinery  on 
the  ordinary  farm.  Not  all  paints  are  of  equal 
value  for  these  different  jobs.  What  is  good 
for  iron  is  not  good  for  concrete,  and  the  paint 
which  is  so  satisfactory  on  the  house  may  be  of 
little  value  for  the  wagons.  A  paint  for  wood- 
work consists  of  some  dry  material  for  colour- 
ing, a  lead  or  a  zinc  base,  a  drier,  and  a  vehicle  or 
liquid.  It  is  the  vehicle  which  is  often  wrongly 
chosen,  and  in  some  ready-mixed  paints  the 
vehicle  is  the  part  which  is  most  likely  to  be 
adulterated.  For  outdoor  work,  except  decora- 
tions, boiled  oil  is  considered  to  be  the  best. 
For  indoor  work  linseed  oil  and  turpentine  are 

43 


44  FARM    ENGINEERING 

preferably  used.  A  little  drier,  litharge  for  dark 
paints  and  sugar  of  lead  for  light  paints,  should 
be  added  to  each  batch  of  paint  mixed. 

Undoubtedly  linseed  oil  paints  are  more  ex- 
pensive than  others,  but  they  are  well  worth  the 
difference  in  price.  This  oil  enables  the  paint 
to  spread  well,  dry  hard  and  opaque,  and  leave 
a  protecting  skin  over  the  wood  surface.  If 
adulteration  is  practised  with  resin  oils,  mineral 
oils,  or  fish  oils,  the  paint  will  either  remain 
sticky  forever  or  will  harden  quickly  only  to 
soften  again  in  a  week  or  ten  days.  Particularly 
should  dark-coloured  paints  be  looked  upon  with 
suspicion  unless  purchased  from  a  thoroughly 
reliable  dealer,  because  such  paints  when  cheap 
usually  contain  only  unrefined  resin  oils  which 
soften  up  within  two  weeks  of  the  first  drying. 
They  never  harden  again  but  give  constant 
trouble. 

One  of  the  best  paints  for  roofs  and  ma- 
chinery is  a  mixture  of  red  lead  and  linseed  oil. 
Another  good  metal  paint  is  known  as  asphal- 
tum  varnish.  It  may  be  purchased  ready  for 
use,  and  when  applied  leaves  a  splendid  wear- 
ing, shiny  black  surface  which  thoroughly  pro- 
tects the  metal. 


PAINTS    AND   PAINTING  45 

For  painting  jobs  requiring  the  covering  of 
a  large  surface,  the  paint  may  usually  be 
sprayed  with  much  less  labour  than  if  the  ap- 
plication is  made  with  a  brush.  Almost  any 
paint  may  be  so  applied  if  it  is  made  thin 
enough.  Use  the  ordinary  spraying  apparatus 
which  is  used  for  disinfecting  and  orchard 
spraying.  It  may  be  readily  cleaned  and  will 
suffer  no  injury  by  such  use.  Probably  white- 
wash is  more  often  applied  in  this  way  than  any 
other  paint.  Particularly  for  fences  and  out- 
buildings this  method  means  a  great  saving  in 
time.  Yet  ordinary  whitewash  is  not  as  econ- 
omical as  cement  whitewash.  While  the  for- 
mer requires  frequent  renewals,  the  cement  wash 
often  remains  satisfactory  following  several 
years'  wear.  The  combination  is  best  made  in 
the  following  proportions:  Mix  together  one 
peck  of  white  lime,  a  peck  and  one  half  of  hy- 
draulic cement,  six  pounds  of  umber,  and  four  of 
ochre.  The  lime  is  first  slaked  and  mixed  with 
two  ounces  of  lampblack  moistened  with  vine- 
gar. Then  add  the  other  ingredients.  Allow 
the  paint  to  stand  for  three  hours  or  longer, 
stirring  occasionally.  The  addition  of  half  a 
pound  of  Venetian  red  renders  the  appearance 


46  FARM    ENGINEERING 

more  pleasing  and  adds  to  the  value  of  the 
paint.  If  ordinary  whitewash  is  used  at  all  the 
addition  of  a  little  glue  or  a  small  amount  of 
flour  mixed  with  boiling  water  and  poured  in 
while  hot  will  prevent  the  whitewash  rubbing 
off  so  readily. 

For  finished  interior  work,  varnishes  are  best 
to  use.  They  give  an  extremely  hard  surface, 
which  protects  the  wood  beneath,  and  they  are 
easy  to  clean  thoroughly.  It  is  not  advisable 
for  any  one  but  an  expert  to  attempt  to  mix 
them  at  home,  for  many  good  ones  are  on  the 
market,  as  well  as  many  worthless  mixtures 
called  varnishes.  True  varnish  is  a  solution  of 
resins  or  gums  in  some  suitable  liquid  such  as 
alcohol  or  oil  of  turpentine  mixed  with  linseed 
oil.  Those  in  which  alcohol  acts  as  the  solvent 
are  spirit  varnishes  and  are  inferior  in  many 
ways  to  the  oil  varnishes,  chiefly  because  the 
alcohol  evaporates  entirely,  leaving  the  varnish 
so  hard  as  to  easily  crack  and  chip.  The  oil 
varnishes,  on  the  other  hand,  should  never  get 
brittle. 


CHAPTER   VII 

Lightning  Rods  and  Rodding 

Evaporation  which  takes  place  at  all  points 
of  the  earth's  surface  is  believed  to  cause  elec- 
trification of  the  particles  of  moisture  in  the 
atmosphere.  As  these  particles  unite  to  form 
clouds,  the  clouds  become  charged  with  elec- 
tricity. The  potential  of  each  cloud  rises 
higher  and  higher  and  the  earth  beneath  be- 
comes charged  by  influence,  or,  as  scientists 
say,  by  induction.  This  induced  charge  on  the 
earth  is  of  opposite  sign  from  the  charge  on  the 
cloud.  Presently  the  difference  in  potential 
between  the  cloud  and  the  earth  becomes  so 
great  that  the  air  between  them  breaks  down 
and  a  passage  of  electricity  takes  place.  This 
is  the  lightning  spark.  This  spark  discharges 
only  the  electricity  accumulated  on  the  under 
surface  of  the  cloud,  and  when  that  discharge 
takes  place  the  cloud  must  adjust  itself  again, 
and  it  does  so  by  discharges  between  the  parts 

47 


48  FARM    ENGINEERING 

of  the  cloud  so  that  there  is  much  internal 
action,  which  accounts  for  the  apparent  boiling 
of  the  upper  part  of  the  cloud.  When  the  cloud 
is  readjusted,  further  sparking  can  take  place 
from  the  same  under  surface,  which  explains  why 
many  lightning  discharges  take  place  during  the 
same  storm. 

Sometimes  the  cloud,  in  place  of  discharging 
to  the  earth,  discharges  to  another  cloud.  If 
that  other  cloud  is  of  small  capacity  it  may 
overflow  and  discharge  to  the  earth.  These 
charges  are  often  disastrous  for  reasons  given 
later. 

Now,  if  there  were  a  conductor,  such  as  a 
metal  rod,  extending  from  the  cloud  to  the  earth, 
the  charges  would  be  equallized,  without  a  light- 
ning spark,  by  a  passage  of  the  electricity  over 
the  rod.  As  there  is  no  such  conductor,  the 
spark  chooses  the  easiest  path  to  follow — the 
line  of  least  resistance.  That  accounts  for  its 
jagged  appearance,  as  the  easiest  path  may  not 
always  be  the  straightest  path.  Dust  particles, 
a  current  of  moist  air,  a  current  of  hot  air,  or  a 
draft  is  very  likely  to  be  followed,  as  such  are 
better  conductors  than  cold,  clean  dry  air. 

The  protection  of  barns  or  other  buildings 


-Showing  the  discharge  between  clouds  and 
the  overflow  to  earth 


LIGHTNING   RODS    AND   RODDING  49 

from  lightning  involves,  then,  providing  an  easy- 
path  for  the  lightning  to  follow  to  the  ground, 
for  it  must  reach  the  ground  and  will  choose  its 
own  way,  however  disastrous,  unless  we  choose 
for  it. 

When  the  earth  is  charged  beneath  a  charged 
cloud,  the  buildings  are  charged,  too,  and  being 
nearer  to  the  cloud  are  apt  to  be  struck  unless 
the  charge  is  dissipated.  It  has  been  found 
that  if  an  electrically  charged  body  be  connected 
to  a  metal  point,  the  charge  rapidly  leaks  off  the 
point.  This,  then,  is  the  second  function  of  a 
lightning  rod — to  dissipate  the  accumulated 
charge  on  a  building,  and  thus  prevent  it  from 
being  struck.  This  cannot  be  done,  however, 
in  the  case  of  overflow  charges  as  described 
above,  because  the  overflow  takes  place  so  sud- 
denly. Hence,  those  strokes  are  particularly 
dangerous. 

From  the  standpoint  of  lightning  protection, 
then,  if  the  barn  doors  and  windows  are  left 
open,  there  is  a  great  draft  which  may  offer  a 
path  to  the  lightning  discharge,  and  there  can 
be  no  adequate  protection  from  lightning  at 
the  doors  and  windows  if  they  are  open.  There 
is,  too,  considerable  heated  air  and  some  dust 


5° 


FARM    ENGINEERING 


passing  out  which  offer  an  easy  path  for  the 
lightning,  and  a  lightning  charge  passing  in- 
side the  barn  is  sure  to  set  the  hay  on  fire.  On 
the  other  hand,  if  the  doors  and  windows  are 
shut  and  ventilation  provided  at  the  top  for  the 
steam  to   escape,  there   may   be  two   crossed 


'.t«vm   jo-u. 


Fig.    9. — Lightning    protection    for    the    roof   ventilator, 
wire  should  make  no  sharp  bends 


The 


arches  of  metal  over  the  opening  with  a  sharp 
metal  point  at  their  joint  and  connected  by  a 
direct  line  to  ground,  thus  affording  reasonably 
good  lightning  protection  should  the  warm  air  act 
as  a  conductor  for  the  lightning  stroke.    More- 


LIGHTNING   RODS   AND   RODDING  5 1 

over,  the  upward  flow  of  moist,  warm  air  over 
the  point  would  help  greatly  to  cause  any  charge 
accumulated  in  the  barn  to  leak  off  the  point,  if 
the  whole  system  of  protection  was  connected 
to  the  point.  Then,  if  the  barn  is  well  rodded, 
and  the  ventilating  opening  properly  protected, 
there  is  not  so  much  danger  that  the  hay  will  be 
set  on  fire  even  if  lightning  strikes  the  barn,  as  it 
will  reach  the  ground  probably  without  going 
inside. 

Absolute  security  from  lightning  can  be 
obtained  only  by  a  large  outlay  of  money.  If 
the  building  to  be  protected  is  well  insured,  and 
a  fire  would  mean  merely  the  loss  of  the  building 
but  no  loss  of  life,  it  is  not  a  business  prop- 
osition to  expend  much  money  for  additional 
protection  in  the  form  of  lightning  rods.  On 
the  other  hand,  if  the  building  is  not  heavily 
insured  or  if  a  fire  would  be  disastrous,  it  is  a 
paying  investment  to  rod  the  building  well. 

The  only  way  to  completely  protect  a  build- 
ing is  to  enclose  it  wholly  in  metal  and  care- 
fully connect  the  metal  to  the  ground.  This  is 
usually  too  expensive,  so  that  as  a  compromise  a 
building  is  enclosed  in  a  network  of  wire  and  the 
latter  well  grounded.  This  is  the  plan  used  on  the 


52  FARM    ENGINEERING 

White  House  and  on  the  Washington  Monument, 
the  only  important  government  buildings  rodded 
at  all.  It  is  the  practice  followed  abroad  exten- 
sively, and  has  been  recommended  many  times 
by  leading  experts  and  engineers. 

There  are  several  other  fundamental  consider- 
ations. The  metal  of  the  rod,  the  joints  between 
the  parts,  the  nature  of  the  ground  connection,  the 
fastening  of  the  rod  to  the  building,  and  the  con- 
struction of  the  discharge  points  all  require  care- 
ful thought  and  workmanship. 

As  to  the  choice  of  metals,  prominent  scien- 
tists differ  in  theory,  although  all  agree  on 
practical  details.  There  is  no  question  but  that 
copper  is  a  better  conductor  of  electricity  or- 
dinarily than  iron  or  any  other  common  metal. 
Yet  a  discharge  of  lightning  differs  from  the 
ordinary  passage  of  electricity  in  so  many  re- 
spects that  the  metal  which  is  best  in  ordinary 
use  may  not  be  best  as  a  lightning  rod.  As  long 
as  the  metal  is  in  first  class  condition,  the  joints 
perfect,  and  the  whole  thing  well  protected 
from  the  weather  so  that  it  won't  oxidize  or  rust, 
any  metal  will  give  satisfactory  service.  The 
chief  advantage  of  copper  is  that  it  will  stand 
the  weather  better  than  iron,  but  the  latter 


LIGHTNING   RODS    AND    RODDING  53 

when  galvanized  and  painted  will  last  a  long 
time  and  is  cheap. 

If  copper  is  used,  the  stranded  or  braided 
cable  is  cheaper,  lighter,  and  better  than  the 
solid  wire  or  rod.  If  this  cable  is  obtained 
hollow,  there  is  a  still  greater  saving,  for  the 
interior  of  lightning  conductors  is  not  used  in 
the  passage  of  electricity  but  is  worthless  except 
to  give  mechanical  strength. 

Whatever  metal  is  chosen,  it  must  be  kept  in 
first  class  repair  at  all  times,  or  it  will  be  of  no 
value.  Abroad  many  of  the  governments  use  two 
strand,  galvanized, barbed  iron  wire  entirely,even 
for  important  work.  The  barbs  are  kept  sharp 
and  the  wire  kept  free  from  rust.  With  these 
precautions  such  a  system  will  give  satisfaction. 

The  chief  use  of  a  lightning  rod  is  to  pre- 
vent a  stroke  of  lightning  taking  place  rather 
than  in  conducting  a  discharge  to  earth,  al- 
though the  latter  must  be  provided  for.  The 
barbed  wire  is  particularly  desirable  because  of 
its  multiplicity  of  sharp  points,  whereby  what  is 
known  as  the  "silent  discharge"  can  take  place 
from  a  building.  This  prevents  the  gradual 
accumulation  of  an  electrical  charge,  and  no 
lightning  stroke  can  take  place.     At  suitable 


54  FARM    ENGINEERING 

intervals  on  large  buildings  larger  sharp  points, 
say  six  to  eight  inches,  should  be  placed  in  a 
vertical  position  and  well  soldered  to  the  main 
rodding.  The  large  points  should  in  every  case 
be  as  nearly  vertical  as  it  is  possible  to  get  them. 

For  a  ground  connection,  it  is  not  sufficient 
to  stick  the  end  of  the  rod  in  the  ground.  Such 
carelessness  might  prove  disastrous.  The  ground 
is  the  vital  part  of  the  whole  rodding  system, 
and  too  much  care  cannot  be  given  to  it.  The 
grounding  device  should  be  buried  at  least  ten 
feet  deep  in  moist  earth,  and  should  be  per- 
fectly connected  to  the  main  rod  by  welding  or 
soldering.  It  should  be  thoroughly  protected 
from  rust  or  other  deterioration,  and  care  should 
be  taken  that  the  earth  is  closely  packed  around 
the  rod  where  it  enters  the  ground.  The  best 
grounding  arrangement  is  a  large  piece  of  metal 
or  a  very  large  bundle  of  wire,  particularly 
barbed  wire. 

To  show  just  how  the  rules  laid  down  above 
should  be  applied,  we  may  take  the  case  of  a 
barn  for  example.  Assume  that  an  inexpensive 
system  is  desired,  and  so  barbed  wire  is  to  be 
used.  First,  lay  a  double  strand  along  the 
ridge  pole  from  the  back  peak  to  the  forward 


LIGHTNING   RODS    AND   RODDING 


55 


peak,  then  down  the  sloping  edge  of  the  roof  to 
the  eaves,  along  the  eaves,  up  the  sloping  edge 
at  the  back  end  to  the  peak,  down  on  the  other 
side  and  along  the  opposite  eaves,  up  the  remain- 


Fig.  10. — The  method  of  bending  barbed  wire  to  form  an  en- 
closing network  for  lightning  protection 

ing  sloping  edge  to  the  front  peak  where  we 
started  from.  Here  we  may  cut  the  wire,  leav- 
ing a  length  of  four  or  five  inches,  which  should 
be  tightly  bound  to  the  first  wire  with  copper 


56  FARM    ENGINEERING 

wire.  This  joint  should  be  flooded  with  solder. 
At  the  back  eaves  sufficient  wire  must  be  left  to 
reach  down  to  the  grounding  device.  Where 
this  ground  wire  crosses  the  other  the  two  should 
be  bound  together  and  soldered. 

About  every  eight  feet  along  the  ridge  a  cross 
wire  is  placed,  extending  down  to  the  eaves  wire 
on  each  side,  the  joints  all  being  bound  and 
soldered.  If  the  barn  has  a  gabled  roof,  another 
wire  should  extend  along  the  outer  ridges,  being 
carefully  connected  to  every  cross  wire.  All 
the  wires  must  be  fastened  directly  to  the  wood 
by  means  of  double  pointed  staples.  Under  no 
circumstances  should  insulators  be  used,  as  they 
render  the  whole  system  useless.  Moreover,  all 
metal  on  or  near  the  barn  must  be  connected  to 
the  lightning  rod.  Any  wire  fences  nearby  must 
be  connected  to  the  ground  wires.  It  is  well, 
also,  to  thoroughly  connect  all  wire  fences  on 
the  farm  to  the  ground  at  intervals  of  fifty  feet, 
as  by  so  doing  stock  standing  near  the  fence 
in  a  thunderstorm  will  not  be  in  danger. 

The  ground  wires  for  the  barn  should  extend 
from  all  of  the  lower  eaves  corners  and  from  the 
back  peak  directly  to  the  ground  in  as  straight 
a  line  as  possible.     They  should  hug  the  wood- 


LIGHTNING    RODS    AND    RODDING  S7 

work  closely,  but  not  follow  all  of  the  bends  and 
corners.  If  the  door  is  on  the  long  side,  a 
ground  wire  should  extend  also  from  the  front 
peak.  Each  ground  wire  must  be  bound  to  the 
top  network  and  soldered  or  welded. 

For  each  grounding  device,  coil  up  a  hundred 
feet  of  the  barbed  wire  in  a  ball  and  bury  it  ten 
feet  deep.  This  can  be  a  continuation  of  the 
ground  wire.  In  covering  the  ball  add  water  to 
the  dirt  as  it  is  thrown  back  in  the  hole,  and  it 
can  be  stamped  down  much  tighter  around  the 
grounding  device  than  if  dry  earth  is  used. 

At  both  peaks  and  about  every  twenty-five 
feet  along  the  ridge  erect  sharp  points  six  or 
eight  inches  long.  Preferably  they  are  made  of 
heavy  copper  wire  filed  to  a  point  at  one  end. 

The  bottom  end  may  be  bent  for  binding  and 
soldering  to  the  wire  on  the  ridge  pole.  Similar 
points  should  be  placed  along  all  the  ridges  on  a 
gable  roof. 

If  the  work  is  properly  and  carefully  done, 
the  result  will  be  a  wire  cage  solidly  joined 
throughout  and  completely  covering  the  barn. 
The  wire  will  have  a  multitude  of  sharp  points 
and  will  be  thoroughly  connected  to  the  ground 
in  several  places.     In  the  case  of  a  very  long 


58  FARM    ENGINEERING 

barn  there  should  be  extra  ground  wires  from 
the  eaves  down  at  the  middle  points  of  the  long 
sides.  The  whole,  except  the  copper  points,  may 
be  well  painted  frequently. 


PART  II 

FARM  WATER  SUPPLY  AND  SEWAGE 
DISPOSAL 

The  Sources  of  a  Pure  Water  Supply. 
Running  Water  for  Fifteen  Dollars. 
A  Sand  Filter  for  Rain  or  Brook  Water. 
Softening  Hard  Water. 
The  Hydraulic  Ram  and  the  Ram-pump. 
Disposal  of  House  Sewage. 


CHAPTER  VIII 
The  Sources  of  a  Pure  Water  Supply 

To  have  a  real  knowledge  of  the  conditions 
likely  to  affect  water  purity  the  farmer  must 
know  the  essential  features  of  good  wells  and 
springs  and  how  to  protect  them  from  contam- 
ination. It  is  with  the  hope  of  acquainting  him 
with  these  problems  and  their  solution  that  this 
chapter  is  written. 

The  distance  to  the  water  table  or  water 
level  determines  how  deep  a  well  must  be  dug 
into  the  soil,  for  to  be  successful  it  must  go  be- 
low the  level  of  the  water  table.  Then  the 
water  will  find  it  easier  to  flow  into  the  well 
from  the  soil  immediately  around  the  opening 
than  to  continue  to  seep  on  to  the  impervious 
layer.  This  causes  a  lowering  of  the  water 
level  around  the  well,  or  a  cone  of  depression  as 
it  is  called.  The  water  still  farther  out  flows 
sideways  into  the  depression  and  on  into  the 
well.     Finally,  the  level  of  the  water  in  the  well 

61 


62  FARM    ENGINEERING 

is  the  same  as  that  in  the  surrounding  water 
table.  If,  now,  some  of  the  water  is  pumped 
out  of  the  well,  its  level  lowers  and  water  flows 
in  from  the  soil  around  it.  Obviously,  then, 
the  deeper  the  well  is  below  the  water  table  the 
greater  its  capacity  will  be  and  the  faster  it  will 
fill  up  as  water  is  pumped  away,  because  the  head 
of  water  causing  the  flow  into  the  well  is  the 
distance  the  surface  of  the  well  water  is  below 
the  level  of  the  water  table. 

Rain  water  as  it  falls  from  the  clouds  is  as 
pure  as  can  be  after  the  first  fall  has  washed 
the  impurities  out  of  the  air.  When  it  strikes 
the  ground  it  becomes  contaminated  with  the 
various  impurities  on  the  surface.  As  it  sinks 
through  the  soil,  however,  these  impurities  are 
taken  out  of  the  water  partly  by  the  bacteria 
which  are  so  plentiful  in  the  upper  soil  layers, 
partly  by  filtration  or  straining,  and  partly  by 
the  chemical  action  of  substances  in  the  soil. 
In  order  that  the  purification  shall  take  place, 
the  water  must  sink  through  a  considerable 
amount  of  soil,  at  least  fifteen  to  twenty  feet. 
A  dug  well  should  be  so  constructed  that  only 
water  which  has  been  so  purified  can  enter  it. 
This  means  not  only  that  the  well  curb  must 


PURE    WATER    SUPPLY  63 

be  something  more  than  ten  inches  above  the 
surrounding  soil  to  keep  out  the  surface  flow, 
toads,  rats,  and  other  foreign  matter,  but  the 
well  must  be  lined  in  a  watertight  manner,  as 
by  concreting  or  with  stone  or  brick  set  in 
mortar  to  a  depth  of  from  fifteen  to  twenty 
feet  below  the  surface.  This  lining  should  be 
pressed  tightly  against  the  earth  so  that  water 
cannot  under  any  circumstances  get  into  the 


Fig.  11. — The  proper  arrangement  for  the  top  of  a  dug  well. 
Curb  high,  cover  tight,  ground  sloping  away  from  well,  trough 
at  one  side 

well  unless  it  has  filtered  through  the  soil  to  the 
depth  of  the  bottom  of  the  waterproof  wall. 
The  top  of  the  well  should  be  closed  with  a 
waterproof  cover  so  that  no  drippings  or  splash- 
ings  can  run  in.  The  horse  trough  should  not 
be  at  the  top  but  should  be  a  few  yards  to  one 
side  so  that  the  drainings  may  not  work  them- 
selves directly  into  the  well  water.     The  location 


64  FARM    ENGINEERING 

of  outbuildings,  manure  piles,  pig  stys,  cattle 
runs,  etc.,  should  be  as  far  away  from  the  well 
as  possible,  and  greatly  below  the  well  if  possible. 
It  is  much  more  important  to  consider  the  matter 
from  the  standpoint  of  health  than  from  that  of 
personal  convenience.  The  direction  of  the 
flow  of  the  underground  water  to  the  well  can- 
not be  altogether  determined  by  the  contour 
of  the  surface  of  the  land.  Moreover,  long- 
continued  pumping  at  the  svell  may  drain  the 
water  into  the  well  from  a  greater  distance 
than  would  otherwise  be  the  case.  Hence,  no 
precaution  should  be  more  carefully  observed 
than  that  of  getting  the  sources  of  possible 
contamination  as  far  away  as  can  be.  The  fact 
that  the  well  is  above  the  privy  does  not  mean 
that  the  drainage  from  the  latter  cannot  reach 
the  well.  It  is  distance  that  counts,  because 
that  can  be  depended  upon  while  a  point  ap- 
parently below  the  well  may,  when  underground 
flow  is  considered,  be  above  and  draining  di- 
rectly into  the  well. 

It  is  apparent  that  a  dug  well  is  not  always 
dependable  unless  certain  precautions  are  taken. 
On  the  other  hand,  deep  wells  are  quite  likely 
to  yield  water  of  perfect  purity,  as  far  as  harm- 


PURE   WATER   SUPPLY  65 

ful  ingredients  go.  The  reason  for  this  is  that  a 
deep  well,  such  as  drilled  or  driven  well  of 
several  hundred  feet,  reaches  a  water-contain- 
ing layer  which  lies  between  two  nonporous 
layers  of  soil.  Somewhere,  probably  miles  and 
miles  away,  the  water  has  entered  this  channel 
and  has  filtered  through  the  soil  for  that  great 
distance,  losing  all  of  its  bad  contents. 

An  artesian  well  is  of  the  same  nature,  but  in 
this  case  the  well  opening  is  made  at  a  point  so 
far  below  the  point  of  entry  of  the  water  in  this 
channel  that  the  head  of  water  is  sufficient  to 
force  water  to  the  surface.  In  almost  all  deep 
wells  the  water  rises  in  the  pipe  above  the  layer 
in  which  it  flows.  The  main  precaution  to  take 
with  deep  wells  is  to  be  sure  the  well  casing  is 
watertight  so  that  no  subsoil  or  surface  water 
can  by  any  means  get  into  the  well. 

Springs,  as  a  rule,  furnish  pure  water  unless 
the  immediate  vicinity  gives  cause  for  contami- 
nation. The  reason  is,  as  stated  previously, 
that  the  water  has  flowed  for  some  distance 
through  the  soil.  The  exception  is  a  spring  in  a 
rocky  district  where  the  water  has  not  sunk 
through  any  great  amount  of  soil,  but  has  merely 
percolated  through  and  over  the  rocks,  finally 


66  FARM    ENGINEERING 

coming  to  light  at  a  convenient  point.  Such 
spring  water  should  be  used  with  care  and  only 
after  strict  examination  of  the  surroundings 
of  the  stream  course.  If  a  spring  is  used  as  a 
water  supply  source,  surface  drainage  in  the 
vicinity  should  be  made  good  to  prevent  any 
surface  waters  from  manured  land  reaching 
the  water  course.  The  best  treatment  is  to 
house  the  spring  in,  leading  a  trough  from  the 
spring  to  a  sunken  storage-basin  which  is  water- 
tight and  tightly  covered.  Then,  from  a  few 
inches  above  the  bottom  of  this  cistern,  lead  the 
supply  pipe  to  the  house  or  barn. 

Rain  water  is,  as  mentioned  above,  a  pure 
form  of  water  except  in  so  far  as  it  is  contami- 
nated by  the  atmosphere.  Because  of  this,  in 
some  districts  it  is  quite  generally  gathered  and 
stored  in  cisterns  for  household  use.  If  prop- 
erly handled,  there  is  slight  danger  of  harmful 
impurities  entering  the  cistern,  yet,  on  the 
whole,  it  is  not  so  desirable  as  ground  water, 
particularly  at  times  of  the  year  when  dust, 
dirt,  dead  insects,  and  excrement  collect  plenti- 
fully on  the  roof.  The  only  impurities  are 
those  brought  by  the  water  itself  if  the  cistern 
is  made  watertight  with  a  close-fitting   cover. 


PURE    WATER    SUPPLY  6j 

Arrangement  should  be  made  so  that  the  first 
few  minutes'  fall  of  rain  which  has  washed  the 
atmosphere  and  washed  the  roof  from  which 
the  water  is  collected  shall  be  directed  to  waste, 
and  only  the  comparatively  pure  water  falling 
after  this  time  shall  be  allowed  to  enter  the 
cistern.  The  cistern  should  not  be  above 
ground,  for  in  the  summer  months  the  water  will 
warm  up  to  such  a  degree  as  to  promote  the 
growth  of  bacteria  in  the  water  rather  than 
retard  it  as  is  done  with  a  cool  storage.  The 
use  of  a  sand  filter,  such  as  is  described  in  an- 
other article,  is  to  be  highly  recommended  where 
cistern  water  is  used  for  household  purposes. 

It  is  not  only  the  farmer  who  should  be  in- 
terested in  pure  water  supplies  for  the  farm, 
it  is  every  man  who  is  dependent  upon  him  for 
milk  and  produce.  Great  typhoid  epidemics 
are  frequently  traced  to  unsanitary  farm  con- 
ditions, which,  when  once  pointed  out  to  in- 
telligent farmers,  are  quickly  remedied,  for  there 
is  no  class  of  workers  in  this  country  more  anx- 
ious to  better  living  conditions  socially,  morally, 
and  economically  than  the  farmers  of  to-day. 


CHAPTER    IX 
Running  Water  for  Fifteen  Dollars 

Many  country  homes  on  the  farms  of  other- 
wise up-to-date  progressive  farmers  still  lack 
the  great  blessing  of  running  water  in  the 
kitchen.  Often  this  lack  is  due  to  a  belief  that 
the  installation  of  such  a  supply  would  necessitate 
the  outlay  of  a  large  sum  of  money.  Nothing 
is  more  untrue.  A  really  good  and  efficient 
running  water  system  may  be  installed  in  the 
kitchen  for  less  than  fifteen  dollars  on  almost 
any  farm  where  there  is  a  water  supply,  if  the 
farmer  is  willing  to  do  the  work  himself. 

By  reference  to  the  drawing  it  will  be  seen 
that  the  supply  is  assumed  to  be  from  a  well  or 
cistern  near  the  house.  A  pipe  leads  in  through 
the  cellar  wall  and  below  the  frost  line,  then  up 
through  the  first  floor  where  a  small  cistern  or 
tank  pump  is  located.  From  this  force  pump 
the  pipe  line  leads  through  a  check  valve  up  by 
the  sink  to  an  elevated  tank  which  may  be  on 

68 


WATER   FOR   FIFTEEN   DOLLARS  69 

the  second  floor,  in  the  attic,  or  even  on  brackets 
just  above  the  tank.  A  barrel  makes  a  very 
satisfactory  tank,  or,  where  more  water  is  needed, 


I    JW*     I    PUMP 


£ 


Fig.  13. — A  simple  running 
water  system  of  low  cost 


>»>j;j  rssrsr  '  *. 


i  CISTERN     ' 


infj'jr 


•^TTTT-rrrr 


several  barrels  standing  side  by  side  and  con- 
nected at  the  bottom  with  short  lengths  of  pipe. 
On  a  farm  in  northern  New  Jersey  a  farmer 
used  six  barrels  elevated  only  about  six  inches 


70 


FARM    ENGINEERING 


above  the  sink  and  placed  on  a  shelf  in  the 
pantry,  the  supply  pipe  to  the  sink  faucet  going 
through  the  pantry  wall  to  the  sink  on  the 
kitchen  side. 


Fig.  14. — A  simple  pneumatic  equipment 

The    pump    recommended    is    the    common, 
low-down,  single  or  double  acting  force  pump. 


WATER   FOR   FIFTEEN    DOLLARS  71 

It  will  cost  from  $6  to  #8.  The  check  valve 
just  beyond  the  pump  will  cost  about  65  cents. 
It  is  a  particularly  valuable  accessory,  for  it 
allows  the  water  to  flow  from  the  pump  to  the 
tank  but  will  not  permit  it  to  flow  out  in 
any  way  except  through  the  sink  faucet.  The 
result  is  that  the  pressure  of  the  water  in  the 
tank  is  not  continually  on  the  pump  piston. 
If  desired,  a  second  pipe  to  another  sink  or  to  a 
handy  faucet  over  the  stove  may  be  led  off  from 
any  point  between  the  check  valve  and  the  tank. 
A  good  tank  is  formed  by  securing  a  barrel 
such  as  oil  is  shipped  in,  burning  out  the  oil,  and 
thoroughly  cleaning.  In  the  barrel  place  a 
small  board  as  a  float  and  run  a  string  over  the 
edge  of  the  barrel  to  some  point  easily  seen. 
Then  hang  a  weight  on  the  end  of  this  string 
and  tack  up  a  paper  or  board  marked  as  an  in- 
dicator so  that  by  the  position  of  the  weight  you 
can  tell  how  near  empty  the  barrels  are  and 
whether  or  not  a  new  supply  should  be  pumped. 
One-inch  pipe  is  large  enough  for  all  uses  and 
one-half-inch  pipe  will  give  satisfaction  for  the 
stretch  between  the  pump  and  the  tank.  It  is 
best  to  use  galvanized  iron  pipe,  although  black 
pipe  is  cheaper  and  does  well  if  kept  painted. 


72 


FARM    ENGINEERING 


If  a  little  more  money  may  be  invested  this 
system  may  be  readily  enlarged  to  give  running 
hot  water,  as  shown  in  the  next  figure.     A  pipe 


TO  TdVK 


Fig.  15. — Illustrating  the  simplicity  of  the  hot- 
water  system  in  connection  with  the  cold-water  ar- 
rangement of  Fig.  13 


WATER   FOR   FIFTEEN    DOLLARS  73 

is  led  from  the  cold-water  pipe  to  the  bottom  of 
a  thirty-gallon  galvanized  iron  tank  costing 
about  $$•  From  the  top  of  this  tank  the 
hot-water  pipe  goes  to  the  sink.  In  the 
stove  is  placed  a  coil  of  pipe,  called  a  waterfront, 
and  costing  about  #3.50.  It  is  piped  to  the 
tank,  one  end  going  to  the  bottom  and  the  other 
connecting  about  eighteen  inches  above.  The 
tank  will  be  drilled  for  connections,  and  the 
connections  furnished  for  the  price  given  above. 
The  water  in  the  waterfront  becomes  heated, 
rises  through  the  coil,  passes  into  the  boiler,  and 
rises  to  the  top  where  it  may  be  led  off  through 
the  hot-water  pipe.  Meanwhile,  cold  water 
from  the  supply  has  passed  down  through  the 
lower  connection  into  the  waterfront.  This  cir- 
culation continues  over  and  over  so  that  finally 
the  tankful  of  water  becomes  hot. 

It  is  readily  seen  that  branch  pipes  may  be 
led  from  these  hot  and  cold  water  pipes  to  any 
part  of  the  house  below  the  storage  tank.  If 
the  tank  is  in  the  attic,  it  is  possible  to  have  a 
bathroom  on  the  second  floor  and  have  set  tubs 
in  the  cellar  for  washing  at  only  the  extra  cost 
of  the  tubs  themselves  and  enough  pipe  to  lead 
the  water  to  them.     Little  by  little,  in  this  way, 


74  FARM    ENGINEERING 

starting  from  the  simple  system  shown  in  the 
first  drawing,  a  splendid  water  supply  arrange- 
ment may  be  built  up,  adding  greatly  to  the 
ease  and  convenience  of  doing  the  daily  tasks  as 
well  as  adding  greatly  to  the  cash  value  of  the 
house. 


CHAPTER    X 

A  Sand  Filter  for  Rain  or  Brook 
Water 

The  use  of  screens,  whether  of  wire  or  cloth 
for  straining  the  water  supply  obtained  from 
brooks,  springs,  and  falling  rain  or  snow  is  ex- 
tremely unsatisfactory  because  of  the  ease  and 
frequency  with  which  they  become  clogged. 
Moreover,  silt  and  fine  particles  are  not  removed 
from  the  water.  The  sand  filter  not  only  strains 
out  the  finest  particles  of  suspended  matter  but 
also  it  has  been  found  by  careful  investigations 
the  water  is  purified  chemically  and  bacterio- 
logically.  To  a  certain  extent  the  filter  allows 
thorough  contact  of  the  water  particles  with  the 
air  as  the  former  trickle  over  the  surface  of  the 
sand  grains. 

Usually  the  water  is  led  to  the  top  of  the  filter 
and  allowed  to  seep  down  through  the  layers  of 
sand  and  gravel  to  the  lower  part  of  the  con- 
tainer, from  which  a  pipe  leads  to  a  storage 

75 


?6  FARM    ENGINEERING 

basin  or  reservoir.  The  house  supply  is  pumped 
from  the  latter.  If  rain  water  is  the  source  of 
supply,  it  is  usual  when  no  filter  is  used  to  allow 
the  first  few  minutes'  fall  to  run  to  waste  in  order 
that  the  impurities  washed  from  the  atmos- 
phere and  from  the  collecting  roof  area  ma}7  not 
enter  the  storage  basin.  If  a  sand  filter  be  used, 
this  need  not  be  done,  although  it  is  very  advis- 
able, for  there  is  no  advantage  in  having  the 
filter  do  more  service  than  is  necessary.  An 
automatic  device  ma}-  be  used  with  safety,  how- 
ever, to  divert  the  first  fall. 

One  acceptable  form  of  filter  is  shown  in  the 
diagram.  There  is  a  receiving  barrel,  a  filter 
barrel,  and  a  storage  receptacle.  The  receiving 
barrel  is  in  such  a  position  as  to  receive  the  water 
directly  from  the  roof  and  pass  it  out  through  a 
smaller  pipe  to  the  top  of  the  filter  barrel.  In 
this  way  no  more  water  is  fed  to  the  filter  than 
can  percolate  through  the  sand  even  if  the  flow 
from  the  roof  is  very  plentiful.  If  brook  water 
is  used,  the  receiving  reservoir  can  be  omitted 
and  a  pipe  laid  from  the  brook  to  the  filter,  or 
the  filter  may  be  made  in  a  watertight  con- 
tainer which  is  buried  in  the  brook  to  such  a 
level  that  the   surface   of  the   brook  water  is 


SAND    FILTER    FOR   RAIN    WATER 


77 


always  slightly  above  the  top  of  the  container. 
In  this  way  water  is  being  freshly  supplied  to 
the  filter  at  all  times.     A  pipe  from  the  bottom 


Fig.  16. — A  satisfactory 
sand  filter 


of  the  filter  leads  to  the  main  storage  basin. 
As  many  receiving  barrels  as  desired  may  be 
joined  together,  and  more  than  one  filter  barrel 
may  be  used  if  it  is  desired  to  filter  the  water  fast. 


78  FARM    ENGINEERING 

At  the  bottom  of  the  filter  barrel  put  a  four- 
inch  layer  of  coarse  gravel  and  on  top  of  that  a 
layer  of  lump  charcoal.  Follow  this  with  three 
layers  of  sand  each  ten  inches  thick,  the  first 
layer  coarse,  the  next  finer,  and  the  top  layer 
quite  fine.  Level  each  layer  off  well  before 
putting  in  the  next.  Both  sand  and  gravel 
should  be  clean  and  free  from  dirt  and  loam. 
It  may  be  necessary  to  wash  them  before  using. 
The  flow  of  water  to  the  top  of  the  sand  should 
be  arranged  so  as  not  to  disturb  the  layer. 
About  three  times  a  year  (not  oftener)  the  top 
four  or  five  inches  of  sand  should  be  scraped  off 
and  replaced  by  a  similar  amount  of  clean, 
fresh  sand.  Even  this  top  layer  must  not  be  of 
the  extremely  fine  sand  sometimes  found,  al- 
though it  is  desirable  to  grade  the  layers. 


CHAPTER  XI 

Softening   Hard   Water 

The  carbonates  and  sulphates  of  lime  and 
magnesia  when  present  in  water  produce  the 
effect  known  as  hardness.  This  term  applies 
merely  to  the  difficulty  with  which  a  lather  is 
obtained  by  using  the  water  with  soap.  It  is 
really  of  interest  therefore  only  in  so  far  as  it 
affects  the  use  of  the  water  for  washing  purposes. 
So  much  of  the  water  obtained  in  the  country 
is  hard  water  that  a  method  of  softening  it 
should  be  of  interest  to  every  one  who  lives  in 
rural  districts.  The  "hardness"  in  the  case  of 
well  water  is  usually  due  to  the  limy  or  chalky 
character  of  the  soil  through  which  the  water 
flows,  the  water  dissolving  some  of  the  lime  con- 
tent of  soil.  The  hardness  is  noticed  because  the 
salts  present  in  the  water  decompose  the  soap 
and  form  a  sort  of  curds  instead  of  a  real  lather. 
If  more  and  more  soap  is  used  the  whole  of  the 
troublesome  material  is  used  up  and  then  a  true 

79 


80  FARM    ENGINEERING 

lather  may  be  formed  without  difficulty.  That 
is,  one  way  of  softening  the  water  consists  in  the 
plentiful  use  of  soap. 

If  the  hardness  is  caused  altogether  by  car- 
bonates spoken  of  above,  it  may  usually  be 
entirely  removed  by  boiling  for  a  short  time. 
In  this  case  the  acid  is  driven  off  with  the  steam 
and  a  precipitate  is  left  in  the  water  which  may 
be  filtered  off  by  pouring  the  water  through  a 
fine  cloth  or  very  fine  screen.  If,  however,  the 
hardness  is  caused  by  the  sulphates,  it  is  what 
is  known  as  "permanent"  hardness  and  cannot 
be  removed  by  mere  boiling  as  "temporary" 
hardness  can.  The  most  common  and  effective 
way  of  removing  permanent  hardness  is  by  the 
addition  of  carbonate  of  soda,  usually  called 
washing  soda.  This  causes  the  formation  of  car- 
bonates instead  of  sulphates,  and  the  carbonates 
may  then  be  removed  by  boiling  and  filtering. 
Frequently  borax  or  ammonia  is  used  in  place 
of  washing  soda. 

There  is  another  rather  interesting  way  of 
removing  the  temporary  hardness.  It  is  by 
the  addition  of  lime  water  (which  is  quicklime 
dissolved  in  water)  or  by  the  addition  of  a  little 
lime.     That  is  the  queer  thing.     By  adding  a 


SOFTENING   HARD   WATER  8 1 

little  lime  to  the  water  you  get  rid  of  the  lime 
already  there.  The  fact  is  that  the  lime  in  the 
water  is  held  there  because  of  the  excess  of 
carbonic  acid.  When  more  lime  is  added, 
this  acid  is  neutralized  and  its  effect  is  lost  so 
that  all  of  the  lime  is  then  precipitated  and  may 
be  strained  or  filtered  off  by  passing  the  water 
through  a  cloth. 


CHAPTER   XII 

The  Hydraulic  Ram  and  the 

Ram-pump 

To  THE  average  person  the  hydraulic  ram  is  a 
mysterious  thing.  Working  day  and  night  for 
years  without  attention  and  without  rest,  it  is 
the  farmer's  most  dependable  friend  for  pump- 
ing water.  The  efficiency  of  the  ram  when  used 
for  lifting  water  only  four  or  five  times  as  high 
as  the  fall  is  as  great  as  that  of  the  best  pumps, 
and  is  much  better  than  that  of  most  pumping 
apparatus.  For  other  ranges  where  the  lift  is 
from  a  small  value  up  to  twenty-five  times  the 
fall  the  following  table  gives  the  efficiency  of  a 
ram: 

TABLE  A 

Lift  divided  by  fall     ...        2  3  4  5 

Per  cent,  efficiency      .      .      .     90%     85%     80%     75% 

Lift  divided  by  fall     ...      10         15         20         25 
Per  cent,  efficiency      .      .      .      S7c"c     4-°c     3°%     23% 

82 


HYDRAULIC    RAM   AND    RAM-PUMP  83 

The  efficiency  of  a  ram  falls  off  so  greatly  as 
the  delivery  height  increases  that  rams  are 
seldom  used  where  the  lift  is  more  than  twenty- 
five  times  the  fall.  For  what  are  known  as 
"  common  rams  "  the  general  rule  for  calculation 
is  that  one  sixth  of  the  water  supplied  to  the 
ram  will  be  lifted  to  a  height  ten  times  as  great 
as  the  fall.  Exact  calculation  may  be  made  for 
any  ram  by  using  the  formula: 

QXHXe 

q=    

h 

where  q  equals  the  quantity  of  water  raised,  in 
gallons,  Q  is  the  quantity  supplied  to  the  ram, 
in  gallons;  h  is  the  lift  from  ram  to  storage  tank, 
in  feet;  H  is  the  fall  from  supply  down  to  ram, 
in  feet;  and  e  is  the  efficiency  of  the  ram  taken 
from  Table  A  above,  where  h  divided  by  H  is 
the  lift  divided  by  fall. 

For  example,  there  is  a  fall  of  ten  feet,  and 
ram  can  be  supplied  with  twenty-five  gallons  of 
water  per  minute.  The  storage  tank  is  in  the 
attic  forty  feet  above  the  ram.  How  much 
water  per  minute  will  be  supplied  to  tank? 
From  Table  A,  the  ratio  of  forty  feet  lift  to  ten 


84  FARM    ENGINEERING 

feet  fall  will  permit  an  efficiency  of  80  per 
cent.  Then,  using  the  figures  given  and  substi- 
tuting them  in  the  formula: 

25  X  10 

q=    X  80  %=  5  gallons  per  minute. 

40 

It  is  apparent  that  if  twenty-five  gallons  of 
water  are  delivered  to  the  ram  and  only  five  gal- 
lons reach  the  tank,  there  must  be  a  great  waste 
of  water.  The  water  is  wasted  but  the  energy 
of  its  fall  is  utilized  in  lifting  the  remaining 
quantity  to  the  greater  height. 

TABLE  B 

SUPPLY  REQUIRED  TO  DELIVER  ONE  GALLON  PER  MINUTE 

Ratio  of  lift  to  fall    .  2  3  4  5 

Gallons   per   minute   re- 
quired to  operate  ram.        2.22      3.47       5.00      6.67 

Ratio  of  lift  to  fall    .      .  10  15  20  25 

Gallons   per   minute  re- 
quired to  operate  ram .      17.54    35  91     66.67     108.70 

A  diagrammatic  form  of  ram  is  shown  in  the 
drawing.     There  are  five  main  parts,  the  drive 


HYDRAULIC   RAM   AND   RAM-PUMP  85 

pipe  A,  the  waste  valve  B,  the  delivery  pipe  D, 
the  air  chamber  C,  and  the  admission  valve  E. 
The  water  flows  down  A  and  out  of  the  waste 
valve  B  when  the  ram  is  first  started.  When 
sufficient  velocity  has  been  gained  by  the  water, 
it  closes  valve  B  suddenly.  This  confines  the 
water  in  the  casing  and,  as  the  movement  of 
such  a  large  bulk  of  water  cannot  be  stopped 


Fig.   17. — Diagram  showing  parts  of  ram  and  ram-pump 


instantaneously,  the  valve  E  is  dealt  a  hammer 
blow  which  opens  it  and  allows  a  small  amount 
of  water  to  flow  into  the  air  chamber.  The 
valve  E  then  falls  shut  again  and,  too,  as  the 
water  has  slowed  down,  the  waste  valve  B  again 
opens,  the  water  flows  out,  gains  velocity,  shuts 
the  valve  B  again,  opens  valve  E,  and   more 


86  FARM    ENGINEERING 

water  is  forced  into  the  air  chamber.  This 
action  continues  indefinitely  as  long  as  water  is 
supplied  to  the  ram. 

The  presence  of  air  in  the  chamber  C  is 
necessary,  for  it  compresses  when  the  sudden 
blow  is  struck  on  the  valve  E,  and  this  allows 
that  valve  to  open.  Of  course  the  water  will 
absorb  a  little  of  the  air  and  after  a  time  the  air 
in  the  dome  will  be  exhausted.  This  will  cause 
the  ram  to  stop  and  to  prevent  such  stoppage 
there  must  be  a  way  of  admitting  more  air  into 
the  air  chamber.  This  is  done  by  boring  a 
small  hole  at  N.  The  water  rushing  into 
chamber  C  sucks  in  through  the  hole  N  just  a 
tiny  bit  of  air,  but  enough  to  prevent  the  ex- 
haustion of  the  air  chamber.  On  many  of  the 
higher  priced  rams  a  "sniffer"  valve  is  located 
at  some  such  point  as  N  to  serve  the  same 
purpose  as  the  tiny  hole  here  recommended. 

The  ram  as  described  above  will  raise  a 
portion  of  the  water  supplied  to  it  to  any  desired 
height.  If,  however,  it  is  desired  to  pump 
clear  water  from  a  brook  or  spring  by  means  of 
undesirable  water  from  some  pond  or  stream,  it 
may  be  done  with  safety  by  using  a  ram-pump. 
This  resembles  the  ram  shown  except  for  the 


HYDRAULIC   RAM   AND   RAM-PUMP  87 

addition  of  the  parts  K,  S,  V,  and  H,  as  shown 
in  the  figure.  As  before,  the  water  to  operate 
the  ram  comes  through  the  drive  pipe,  but  the 
water  to  be  pumped  enters  through  the  small 
pipe  K  and  passes  through  the  valve  E  when 
the  latter  is  opened.  A  check  valve  at  V  pre- 
vents the  clear  water  being  forced  back  up  the 
pipe  K  while  a  stand  pipe  at  S  keeps  sufficient 
water  pressure  on  the  pipe  at  H  to  fill  the  right- 
hand  end  of  the  casing  at  all  times  and  even 
allow  a  little  to  leak  through  the  waste  valve  B. 
Thus,  none  of  the  impure  water  gets  near  enough 
to  the  valve  E  to  be  in  any  danger  of  being 
forced  into  storage.  The  ram-pump  is  best 
used  where  the  supply  of  pure  water  is  decidedly 
limited  in  quantity. 

Rams  and  ram-pumps  are  usually  placed  at 
the  bottom  of  pits  dug  into  the  ground,  the 
head  being  increased  in  that  way  while  the 
waste  water  flowing  from  the  waste  valve  is 
easily  drained  from  the  pit  through  open  joint 
tiles  or  through  a  drain  pipe  laid  from  the  pit  to 
a  lower  level. 

Rams  are  commonly  made  in  six  sizes,  from 
that  requiring  only  one  and  one  half  gallons  per 
minute  to  operate  it  up  to  one  requiring  twenty- 


88  FARM   ENGINEERING 

five  gallons  per  minute.  The  price  ranges  from 
#5  up  to  #25  for  these  sizes.  Larger  sizes  are 
made,  and  often  a  whole  battery  of  rams  are  in- 
stalled where  the  supply  of  water  is  large. 
Ram-pumps  are  slightly  more  expensive.  If 
possible,  the  ram  to  be  purchased  should  be  pro- 
vided with  an  adjustable  arrangement  on  the 
waste  valve  so  that  the  latter  will  not  stick  if 
a  higher  head  is  used  than  was  at  first  thought 
to  be  possible.  If  this  is  not  done,  care  must  be 
taken  that  the  ram  bought  is  workable  on  the 
highest  head  of  water  that  can  be  used  by  you. 


CHAPTER  XIII 

Disposal  of  House  Sewage 

Allowing  sewage  to  flow  directly  into  a 
stream  or  even  into  a  cistern  without  first  re- 
moving the  harmful  content  is  a  serious  mistake, 
and  in  many  states  there  has  been  successful 
agitation  for  punishing  such  an  act  by  fine  or 
imprisonment.  The  most  practical  method  yet 
devised  for  the  disposal  of  house  sewage  with- 
out troublesome  care  and  constant  attendance 
is  the  septic  tank  method.  It  depends  for 
its  value  upon  the  action  of  certain  bacteria 
already  present  in  the  sewage.  The  conditions 
are  made  best  for  the  growth  and  work  of  these 
bacteria,  and  they  are  permitted  to  liquefy  and 
destroy  the  solid  matter  in  the  sewage.  After 
their  action  the  liquefied  remainder  is  disposed 
of  readily  on  any  farm  without  giving  cause  for 
offence.  Such  a  tank  will  not  freeze  in  the 
coldest  climate  if  buried  a  foot  in  the  ground 
and    used    daily.     No   disinfectants   are   used. 

89 


90  FARM    ENGINEERING 

It  will  not  contaminate  a  nearby  well  or  spring 
if  the  tank  is  made  waterproof  by  plastering  the 
walls  with  cement  mortar. 

The  bacteria  utilized  are  of  two  kinds :  Those 
known  as  anaerobic  thrive  and  grow  in  darkness 
away  from  fresh  air.  They  are  permitted  to 
get  in  their  work  on  the  sewage  as  it  first  comes 
from  the  house,  being  led  into  a  tightly  covered, 
watertight,  non-ventilated  underground  tank, 
and  permitted  to  remain  there  undisturbed  for 


Fig.  18. — The  septic  tank 

twenty-four  hours.  At  the  expiration  of  this 
time  it  is  almost  entirely  liquid,  and  may  be  led 
over  a  filter  bed  of  gravel  or  a  well-drained 
trench  filled  with  stone.  Here  the  other  variety 
of  bacteria,  called  aerobic,  assisted  by  the 
oxygen  of  the  air,  transform  the  murky  liquid 
into  a  perfectly  harmless  substance  which  may 
be  permitted  to  flow  over  the  surface  of  the  land, 
or  may  be  discharged  into  a  stream  without  any 
danger  whatever  of  contamination. 


DISPOSAL   OF   HOUSE    SEWAGE  91 

One  of  the  best  forms  for  the  septic  tank  to 
take  is  that  shown  in  the  illustration.  It  con- 
sists mainly  of  a  concrete  box  three  feet  wide, 
eight  feet  long,  and  three  feet  deep.  Three  feet 
from  one  end  is  placed  a  partition  which  is  per- 
forated at  a  number  of  points  in  order  that  the 
liquefied  sewage  may  pass  through  without 
agitation  of  the  entire  contents.  The  inlet  pipe 
must  be  below  the  level  of  the  sewage,  as  it 
stands  in  the  tank  and  the  perforations  spoken 
of  should  be  on  about  the  same  level.  The  out- 
let is  somewhat  higher  than  the  inlet,  but  as  the 
inlet  pipe  slopes  from  the  house  down  to  the 
tank,  the  outlet  will  be  below  the  upper  portion 
of  the  inlet  pipe,  and  thus  the  tank  will  over- 
flow properly.  It  requires  some  time  for  the 
tank  to  get  to  working  in  a  thoroughly  satis- 
factory manner,  but  after  a  little  while  a  thick 
scum  forms  on  the  top  and  must  not  be  disturbed 
or  broken  up.  That  is  the  main  reason  for  in- 
troducing the  inlet  pipe  below  the  surface  of 
the  liquid. 

There  is  a  hole  left  closed  with  a  removable 
but  tightly  fitting  cover  in  the  top  of  the  main 
chamber  in  order  that  the  settlings  at  the 
bottom   may   be   removed   if  found   necessary 


92  FARM    ENGINEERING 

after  a  few  years'  use.  Under  no  other  circum- 
stances should  the  contents  be  disturbed. 
These  settlings,  if  any  are  present,  are  mainly 
mineral  matter,  not  from  the  sewage  itself  but 
from  the  paper  or  other  foreign  substances 
which  enter  the  tank.  The  probabilities  are 
that  it  will  not  need  cleaning  out  for  ten  or  fif- 
teen years. 

The  tank  should  remain  full  up  to  a  certain 
height  at  all  times,  this  height  being  such  that 
all  sewage  will  remain  in  the  tank  about  twenty- 
four  hours  or  slightly  longer.  By  placing  an 
outlet  leading  to  the  filter  bed  at  the  right 
height,  it  may  act  as  an  overflow  for  the  liquid, 
thus  doing  away  with  any  necessity  for  watch- 
ing and  operating  a  valve.  The  outlet  usually 
comes  about  twelve  inches  below  the  surface  of 
the  liquid.  The  inlet  is  usually  about  twelve 
inches  above  the  bottom  of  the  tank.  As  shown, 
the  inlet  should  point  downward  inside  of  the 
tank  as  a  further  guard  against  undue  disturb- 
ance of  the  contents. 

The  filter  bed  consists  of  another  concrete  box 
filled  with  stones  and  gravel  in  order  that  the 
liquefied  sewage  may  trickle  over  it  slowly, 
coming  in  contact  with  the  oxygen  of  the  air 


DISPOSAL    OF    HOUSE    SEWAGE  93 

and  allowing  the  aerobic  bacteria  to  render  the 
fluid  harmless.  From  the  bottom  of  this  filter 
bed  the  purified  sewage  may  be  discharged  to 
any  convenient  place.  The  usual  way  is  to  let 
it  pass  off  through  a  four-inch  tile  drain  fifty  or 
sixty  feet  long  set  with  open  joints.  The  filter 
bed  should  be  well  exposed  to  air  and  light. 
The  sewage  when  flowing  from  the  bed  should 
be  clear,  free  from  odour,  and  should  not  con- 
tain any  poisonous  or  otherwise  harmful  matter. 

The  essential  thing  is  to  understand  the 
simple  theory  of  bacterial  action  which  lies 
back  of  the  septic  tank  process.  If  that  is  once 
firmly  grasped,  the  details  of  tank  building 
may  be  widely  altered  to  meet  particular  needs. 
One  very  successful  modification  of  this  scheme, 
which  has  now  been  in  use  for  several  years, 
consists  of  simply  the  first  tank  spoken  of 
above,  and  no  partition  in  it,  but  simply  an 
overflow  arranged  at  the  proper  height  to 
empty  into  a  number  of  tiled  drains  laid  out 
in  the  form  of  a  network  around  the  tank  and 
about  a  foot  beneath  the  ground.  In  this  way 
the  bacteria  in  the  upper  soil  layers  do  the  final 
work  of  purification. 

The  cost  of  such  a  tank  as  illustrated  here 


94  FARM    ENGINEERING 

should  not  exceed  #15  or  $20  dollars,  being 
near  to  the  former  figure  if  the  cost  of  labour 
is  not  included,  and  near  to  the  other  figure 
if  labour  must  be  paid  for.  This  estimate  in- 
cludes the  purchase  of  cement,  sand,  and  gravel, 
the  lumber  for  the  forms,  the  tile  for  the  drains, 
and  a  hundred  feet  of  vitrified  sewer  tile  for  the 
inlet  pipe. 


PART   III 

FARM    POWER 

Kerosene,  Gasoline,  and  Coal  as  Fuels. 

The  Oil  Tractor  on  the  Small  Farm. 

The  Ignition  System  and  Ignition  Control  of 

the  Gasoline  Engine. 
Determining  the  Horsepower  of  an  Engine. 
Utilizing  Small  Streams  for  Power. 
The  Storage  Battery  for  the  Farm. 


CHAPTER  XIV 
Kerosene,  Gasoline,  and  Coal  as  Fuels 

The  determination  of  the  relative  values  of 
gasoline,  kerosene,  and  coal  for  small  engines 
has  occupied  much  thought  during  the  last  few 
years  because  of  the  constantly  increasing  price 
of  gasoline  and  the  much  cheaper  cost  of  kero- 
sene in  many  parts  of  the  country.  The  prob- 
lem is  somewhat  complicated,  however,  because 
it  is  necessary  to  take  into  account  the  relative 
costs  of  attendance  and  repair  of  the  engines. 

Kerosene  is  a  heavier  distillate  than  gasoline, 
both  being  obtained  from  petroleum.  Theo- 
retically, kerosene  has  a  higher  heat  value  than 
gasoline  in  the  proportion  of  II  to  9,  but  it  is 
difficult  to  obtain  the  full  heat  value  of  kerosene 
in  a  gasoline  engine.  A  much  higher  tempera- 
ture is  required  to  vaporize  it  than  gasoline, 
and  more  evaporating  surface  is  required. 
Then,  within  the  engine,  combustion  is  not  apt 
to  be  complete,  so  that  a  deposit  of  carbon  is 

97 


98  FARM    ENGINEERING 

left  on  the  cylinder  walls,  piston,  and  spark 
plugs,  thus  requiring  frequent  cleaning.  Any 
gasoline  engine  will  run  on  kerosene  if  started 
and  warmed  up  on  gasoline,  and  the  cost  of  fuel 
is  less  than  when  gasoline  is  used  provided  that 
three  gallons  of  the  former  cost  no  more  than 
two  gallons  of  the  latter.  For  example,  using 
these  fuels  on  small  tractor  engines  the  cost  of 
gasoline  at  30  cents  per  gallon  was  70  cents  per 
acre,  and  using  kerosene  at  15  cents  the  cost  for 
fuel  was  50  cents  per  acre.  As  this  shows  you, 
the  amount  of  kerosene  used  ordinarily  is  over 
one  and  one  fourth  gallons  to  one  gallon  of  gaso- 
line. In  an  engine  built  to  consume  kerosene, 
the  kerosene  effects  a  greater  saving  because  of 
the  more  complete  combustion.  Under  those 
circumstances,  for  work  requiring  the  same 
power  for  the  same  length  of  time,  trials  with 
small  engines  have  shown  an  actually  smaller 
consumption  of  kerosene  than  of  gasoline,  the 
latter  being  used  in  a  gasoline  engine. 

In  general,  the  amount  of  fuel  consumed  per 
horsepower  per  day  of  ten  hours  using  gasoline 
is  about  one  gallon,  sometimes  more  but  seldom 
less.  The  amount  of  coal  consumed  in  the  aver- 
age farm  steam  engine  per  horsepower  per  day 


KEROSENE,    GASOLINE,   AND    COAL  99 

varies  from  sixty  to  eighty  pounds  with  ordinary 
firing,  although  an  expert  fireman  could  prob- 
ably cut  that  down  to  forty  pounds.  With  this 
as  a  basis,  you  can  figure  the  cost  of  fuel  in  your 
locality.  Say  gasoline  is  30  cents  a  gallon  and 
coal  is  $5  a  ton,  the  cost  of  gasoline  for  a  ten- 
horsepower  engine  per  day  would  be  #3,  while 
the  cost  of  a  steam  engine  giving  the  same  power 
would  be  (using  sixty  pounds  per  horsepower 
day)  $1.50.  If  kerosene  at  15  cents  a  gal- 
lon is  used  in  the  gasoline  engine,  the  cost 
would  be  about  #1 .88.  It  must  be  remembered, 
however,  that  coal  will  have  to  be  used  for  an 
hour  or  so  getting  up  steam,  and  the  coal  on  the 
grate  at  the  end  of  the  day,  as  well  as  the  heat  in 
the  boiler  at  that  time,  is  all  wasted.  The  cost 
of  the  steam  engine,  therefore,  for  fuel  alone 
will  probably  be  nearer  to  $2  than  $1 .50.  Again 
the  steam  boiler  will  mean  added  cost  because 
of  the  constant  attendance  necessary  in  keep- 
ing up  the  fire  and  keeping  the  water  level  in 
the  boiler  from  getting  too  high  or  too  low.  It 
will  require  attendance  in  getting  up  steam  be- 
fore time  to  use  it,  and  it  will  need  nearly  as  much 
attention  between  spells  of  using  the  engine, 
if  the  fire  is  kept  up,  as  when  the  engine  is  used. 


IOO  FARM    ENGINEERING 

There  are  many  other  points  in  favour  of  the 
oil  engine,  such  as  less  chance  of  explosion,  less 
complication,  and  less  knowledge  necessary  to 
operate  it.  The  interest  on  the  first  cost  of  the 
plant  will  be  less,  and  the  depreciation  should 
be  slightly  less.  Yet  the  steam  engine  has  a 
number  of  points  in  its  favour.  It  can  be  "over- 
loaded." That  is,  by  increasing  the  steam  pres- 
sure in  the  boiler,  the  ten-horsepower  engine 
can  be  made  to  give  twenty  or  twenty-five  horse- 
power for  a  time,  with  increased  coal  consump- 
tion, of  course.  The  exhaust  steam  may  be 
used  about  the  farm  to  heat  water  for  washing 
purposes,  or,  if  properly  arranged,  the  exhaust 
from  a  stationary  engine  may  be  used  to  heat 
outbuildings. 

There  is  an  economic  importance  in  the  use 
of  kerosene  as  a  fuel  in  place  of  gasoline,  for  it 
will  tend  to  lower  the  price  of  gasoline  by  less- 
ening the  demand.  While,  of  course,  by  the 
same  argument  it  will  tend  to  increase  the  price 
of  kerosene,  there  is  such  an  oversupply  of  the 
latter  due  to  its  production  in  great  quantities 
as  a  by-product  in  the  refining  of  gasoline  and 
other  oils,  that  this  tendency  will  not  be  very 
much  felt. 


KEROSENE,    GASOLINE,    AND    COAL  IOI 

All  of  these  things  being  taken  into  consider- 
ation, there  is  no  doubt  as  to  the  greater  value 
of  the  kerosene  engine.  This  is  being  demon- 
strated by  the  constantly  increasing  use  of  it, 
and  a  similar  constantly  decreasing  use  of 
steam  engines  in  proportion  to  the  total  power 
used. 


CHAPTER   XV 

The  Oil  Tractor  on  the  Small  Farm 

While  it  is  certain  that  the  horse  can  never 
be  entirely  dispensed  with  on  the  small  farm, 
the  light-weight  oil  tractor  of  from  six  to  thirty- 
five  horsepower  capacity  is  destined  to  relieve 
him  of  much  of  the  hard  work  which  he  does  but 
slowly  and  which  wears  him  out  in  the  doing.  In 
many  places  where  a  horse  is  valuable  the  tractor 
cannot  be  used,  but  the  decreased  cost  per  acre  of 
farming  with  the  small  tractor  over  that  incurred 
when  using  horses;  the  fact  that  the  tractor 
enables  the  farmer  to  do  without  help  at  just 
the  time  when  help  is  scarce;  the  fact  that  when 
idle  the  tractor  costs  nothing  to  keep;  that  it 
requires  no  rest  even  on  hot  days,  but,  in  emer- 
gencies, can  be  used  all  day  and,  with  lights, 
work  continued  after  dark;  that,  being  small, 
it  is  economical  in  doing  many  things  besides 
plowing — can,  in  fact,  do  all  that  a  portable 
engine  can  do  and,  besides,  propel  itself  where- 


THE    OIL   TRACTOR  IO3 

ever  it  is  wanted;  all  these  advantages  mean 
more  money  to  the  small  farmer  using  such 
power.  He  is  facing  a  new  era  in  agriculture. 
His  land,  in  many  cases,  has  been  so  abused 
in  the  past  by  the  continuous  growth  of  crops 
without  fertilization  that  it  will  require  here- 
after as  much  plant  food  put  into  the  soil  as  is 
taken  out  in  the  crops.  This  means  an  added 
amount  of  work  each  year  which  must  be  done 
at  certain  times.  Labour  is  no  longer  cheap, 
and  satisfactory  farm  help  is  hard  to  get  at  any 
price. 

The  average  work  day  of  a  farm  horse  the 
year  round  is  only  from  three  to  four  hours. 
Yet  he  must  be  fed  the  whole  year  at  a  cost 
averaging,  perhaps,  #100  for  the  twelve  months. 
It  may  not  be  in  cash,  but  in  food  that  would 
sell  for  such  an  amount  if  there  were  no  horse. 
His  field  of  work  is  limited.  Most  of  the  small 
machinery  which  runs  by  belt  power  is  not 
satisfactorily  operated  by  either  a  horse  sweep 
or  a  treadmill,  while  feed  cutters,  silo  fillers, 
threshers,  and  similar  machines  are  too  heavy 
for  the  horse  to  handle.  His  speed  on  the  road 
under  load  is  very  limited,  as  is  his  pulling 
power.     The  time  taken  in   his  care,   the  re- 


104  FARM    ENGINEERING 

pairs  to  harnesses,  the  hitching  and  unhitching 
several  times  daily,  allowing  rest  when  work  is 
waiting,  are  all  features  which  raise  the  operat- 
ing cost  of  a  horse  to  a  high  amount  per  hour 
of  work  he  does.  On  the  other  hand,  the  small 
tractor  can  be  worked  continuously  every  day 
to  plow,  harrow,  drill,  disc,  harvest,  haul,  thresh, 
run  small  machines  or  the  largest  apparatus, 
and  when  it  is  not  needed  the  power  is  im- 
mediately shut  off  and  costs  of  operation  cease. 
The  light-weight  oil  tractor  can  work  in  much 
softer  soil  than  the  larger  sizes  or  even  steam 
machines  of  the  same  rating,  and  on  the  road  it 
can  cross  bridges  and  culverts  which  would 
need  reinforcement  before  the  heavy  steam 
vehicles  or  the  high-powered  gasoline  tractors 
could  be  taken  on  with  safety.  The  following 
tables  give  many  useful  facts  concerning  the 
smaller  size  machines,  and  opportunity  is  thereby 
given  to  compare  the  steam  tractor  with  the 
small  gasoline  types.  Unfortunately,  the  rated 
horsepower  in  the  case  of  steam  tractors  is  not 
actual  horsepower  which  can  be  developed,  but 
is  approximately  half  that  maximum  value. 
An  oil  tractor,  then,  should  be  compared  with 
a  steam  machine  of  half  the  rating. 


THE    OIL  TRACTOR 


ios 


TABLE  i 

TRACTORS     OPERATING     ON     GASOLINE     OR     KEROSENE 


Brake 

Weight 

Drawbar 

Economical 

Horse 

power 

in  lbs. 

pull  in  lbs. 

load  in  lbs. 

equivalent 

dollars 

6 

3,o86 

900 

4,000 

3 

$     600 

8 

3»"5 

I,4l6 

6,000 

5 

725 

12 

3.275 

2,124 

I0,000 

7 

800 

18 

5,025 

3,200 

I4,000 

10 

1,000 

25 

7,5oo 

4,000 

18,000 

13 

I,500 

35 

11,500 

6,000 

26,000 

20 

2,O0O 

TABLE  2 

STEAM   TRACTORS 


Horse- 
power 
ratings 

Weight 
in  lbs. 

Drawbar 
pull  in  lbs. 

Economical 
load  in  lbs. 

Horse 
equivalent 

Diameter 
of  turning 
circle  in  ft. 

15 

20 

25 
30 

I4,000 
20,000 
21,000 
28,000 

4,500 

7,5O0 

9,000 

10,500 

20,000 
26,000 
30,000 
40,000 

15 

25 
30 

35 

35 
40 
40 
45 

The  above  tables  are  representative  and  in- 
clude a  number  of  different  makes  of  tractors, 
all  of  which  are  guaranteed  for  one  year  against 
defects  of  manufacture. 

In  determining  the  size  of  tractor  needed  for 
any  particular  work,  the  following  tables  will  be 
of  interest.  In  reading  them,  it  should  be 
observed  that  drawbar  pull  corresponds  to  the 


io6 


FARM    ENGINEERING 


pull  on  the  traces  by  horses  or  the  pull  on  the 
pole  by  oxen.  It  is  the  pull  which  the  tractor 
will  exert  through  the  medium  of  the  drawbar, 
the  bar  which  couples  the  tractor  to  the  train  it 
draws  after  it. 


TABLE  3 


DRAWBAR    PULL    REQUIRED    FOR    A 
WAGON 


LOAD    OF    ONE    TON    IN 


Good  road 

Gravel 

Sand 

lbs. 

lbs. 

lbs. 

On  the  level      .... 

125 

250 

625 

Rise  of  i  foot  in  ioo  feet 

145 

27O 

645 

"      "    2      "     "       *'       " 

165 

29O 

665 

"  ;;  3  ;;  "   ;   - 

185 

3IO 

685 

4 

205 

330 

705 

"     "    5     "    "      "      " 

225 

350 

725 

"     "    6     "    "      "      " 

245 

370 

745 

TABLE  4 

*DRAWBAR    PULL    REQUIRED     FOR    ONE     PLOW     BOTTOM 


IN   VARIOUS    SOILS 


Sandy 
Clover  sod 
Clay  .      . 
Virgin  sod 
Prairie  sod 
Gumbo    . 


1: 

.-inch  botton 

1 

6-inch 

7-inch 

8-inch 

lbs. 

lbs. 

lbs. 

2l6 

252 

288 

504 

588 

672 

576 

672 

768 

1,080 

I,26o 

1,440 

1,080 

I,26o 

1,440 

1,440 

1,680 

1,920 

*Each  plow  will  turn  about  25  acres  a  day  at  i\  miles  per  hour. 


Fig.  23. — The  past  and  the  present 


Fig.  24. — A  severe  test  for  any  machine 


THE    OIL   TRACTOR 
TABLE  4 — Continued 


IO7 


Sandy 
Clover  sod 
Clay  .      . 
Virgin  sod 
Prairie  sod 
Gumbo    . 


14-inch  bottom 


6-inch 

lbs. 


252 

588 

672 

I,26o 

I,26o 

1,680 


7-inch 

lbs. 


294 

686 

784 

1,470 

1,470 

1,960 


8-inch 

lbs. 


336 

784 

896 

I,68o 

1,680 

2,240 


Sandy 
Clover  sod 
Clay  . 
Virgin  sod 
Prairie  sod 
Gumbo    . 


16-inch  bottom 


6-inch 

lbs. 


288 

672 

768 

1,440 

1,440 

1,920 


7-inch 
lbs. 


336 

784 

896 

1,680 

1,680 

2,240 


8-inch 
lbs. 


384 
896 
1,024 
1,920 
1,920 
2,560 


In  connection  with  Table  4,  it  should  be 
noted  that  in  going  up  a  grade  each  rise  of  one 
foot  in  one  hundred  feet  adds  1  per  cent,  of  the 
weight  of  plows  and  tractor  to  the  pull  required, 
and  in  going  down  such  a  grade  1  per  cent,  is 
taken  off  the  pull  required.  A  plow  gang 
weighs  from  600  to  700  pounds  for  each  bottom, 
so,  for  example,  a  five-plow  gang  would  weigh 
between  3,000  and  3,500  pounds. 


108  FARM    ENGINEERING 

The  cost  of  operation  should  include  not 
only  the  cost  of  fuel,  oil,  labour,  and  repairs,  but 
should  also  include  interest  on  the  investment 
and  depreciation  in  the  value  of  the  machine. 
The  latter  figure  may  be  made  to  allow  for  re- 
pairs also.  Interest  on  the  money  invested 
averages  6  per  cent,  the  country  over.  De- 
preciation, including  repairs,  should  be  charged 
at  10  per  cent,  to  be  on  the  safe  side.  As  to  the 
consumption  of  fuel,  most  of  the  tractors  require 
from  one  and  one  half  to  two  gallons  of  fuel  per 
acre  of  land  plowed,  but  the  time  taken  to  plow 
an  acre  depends,  of  course,  on  the  speed  of  the 
tractor  and  the  number  of  bottoms  pulled.  The 
economical  speed  at  which  a  tractor  should  run 
in  the  fields  is  from  two  to  two  and  one  half 
miles  per  hour.  Slower  than  this  leaves  a  poor 
job,  while  a  faster  speed  does  not  permit  the 
machine  to  exert  its  most  economical  pull.  In 
drawing  a  load  on  the  road,  from  three  and  one 
half  to  five  miles  per  hour  is  a  good  rate  of  travel. 
For  all  operations  requiring  the  use  of  the  trac- 
tor engine  as  a  portable  engine,  an  allowance  of 
about  one  gallon  of  fuel  per  horsepower  exerted 
for  a  nine-hour  run  will  be  ample. 

Average   cost   of  operation,   then,   including 


THE    OIL   TRACTOR  IO9 

everything,  and  allowing  a  fair  sum  to  the 
farmer  for  his  time  in  driving  and  caring  for  the 
machine,  should  not  be  over  75  cents  to  $1  per 
acre  of  land  plowed.  The  cost  per  working 
day  for  a  twenty-five  horsepower  one-man  oil 
tractor  costing,  say,  #1,500,  working  ten  hours 
per  day  for  200  days  in  the  year,  would  be 
about  as  follows: 

TABLE  5 

AVERAGE    COSTS    OF   OPERATION    (APPROXIMATE) 

Interest  at  6%  on  #1,500  $       90.00 

Depreciation  at  10%     .  150.00 

Driver's  time  at  #3  per 

day 600.00  (#5  in  many  sections) 

Kerosene  at  10c.  per  gal- 
lon          540.00     (average   wholesale 

Oil,  grease,  etc.       .      .  100.00               price) 

Total  for  200  days.     $1,480.00 
Cost  per  day         .     $       7.40 

This  machine  at  a  cost  of  $7.40  per  working 
day  will  do  the  work  of  seven  two-horse  teams 
and  drivers,  assuming  that  the  horses  and  drivers 
could  work  ten  hours  per  day  for  200  days 
in  the  year.  If  hired,  seven  two-horse  teams 
with  drivers  would  cost  at  least  $20  per  day. 


110  FARM    ENGINEERING 

If  the  men  were  hired  and  the  horses  owned,  the 
cost  would  be  somewhat  less  than  if  the  whole 
outfit  were  hired,  as  shown  by  Table  6,  which 
follows : 

TABLE  6 

COST   OF   HORSES   AND   HELP 

Assume     first    cost    of 

horses  and  harnesses       #3,000.00 

Interest  at  6%  .      .      .  180.00 

Depreciation  at  10%    .  300.00 

Feeding  and  care    .      .        1,400.00 


Total  for  14  horses      #1,880.00 

Cost  per  day    .      .  9 .  40  (Assuming  200  work- 

Wages,  3  men,  at  $2  6.00       ing  days) 

Cost  per  day,  7  teams 

and  drivers     .      .      .     $      15.40 

Undoubtedly  the  figures  given  in  these  tables 
do  not  apply  to  every  case.  They  are,  however, 
of  value  as  pointing  out  what  things  to  take 
into  consideration,  and  give  some  definite  idea 
of  prices  that  do  obtain  in  some  sections. 


CHAPTER  XVI 

The   Ignition   System  and   Ignition 
Control  of  the  Gasoline  Engine 

As  spring  approaches,  thousands  of  gasoline 
and  kerosene  engines  will  be  brought  into 
service  all  through  the  farming  districts  as 
stationary  and  portable  engines,  operating  all 
kinds  of  farm  machinery,  and  as  automobile, 
tractor,  and  truck-propelling  engines.  Two 
thirds  of  the  difficulties  encountered  in  their 
operation  will  be  due  to  defects  in  the  ignition 
systems,  or  to  lack  of  knowledge  of  the  impor- 
tance of  proper  ignition  control.  The  ignition 
system  is  the  vital  part  of  the  oil  engine,  and  it 
must  work  properly  and  be  controlled  in  the 
correct  manner. 

There  are  two  divisions  of  ignition  systems 
under  which  all  designs  may  be  properly  classi- 
fied :  the  make  and  break  or  low  tension,  and  the 
jump  spark  or  high  tension.  These  names  refer 
to  the  particular  method  by  which  the  spark  in 


112  FARM   ENGINEERING 

the  cylinder  is  made.  With  the  former  design 
there  are  two  contact  points  in  the  cylinder, 
one  of  which  is  movable  and  may  be  turned 
away  from  the  other  suddenly  by  a  spring 
trigger  arrangement,  after  having  been  in  con- 
tact for  a  very  small  interval  of  time.  The  two 
points  are  connected  in  circuit  with  a  battery 
and  a  coil  of  wire  wound  about  an  iron  core. 
When  the  points  are  separated  the  "  momentum" 
of  the  current  causes  it  to  jump  the  gap  created 
between  the  points,  thus  giving  the  required 
spark.  The  purpose  of  the  coil  used  is  to  in- 
crease this  tendency  of  the  current  to  continue 
to  flow  even  after  the  circuit  has  been  broken. 
The  coil  itself  consists  merely  of  a  few  turns  of 
insulated  copper  wire  wound  about  a  soft  iron 
core.  Such  an  arrangement  as  this  has  been 
used  for  many  years  in  electric  gas-lighting 
systems  and  is  there  known  as  a  spark  coil. 
It  is  commonly  referred  to  in  connection  with 
gas  engines  as  a  make  and  break  or  a  non- 
vibrating  coil. 

The  make  and  break  system,  because  of  the 
difficulties  of  mechanical  design,  cannot  be  used 
on  high-speed  engines  nor  on  very  small  sizes. 
It    has    many   advantages    and    many   disad- 


THE    IGNITION    SYSTEM  II3 

vantages  over  the  jump  spark  system.  A 
much  hotter  spark  can  be  obtained  with  the 
make  and  break  because  of  a  greater  flow  of 
current.  There  is  not  so  much  leakage  of  cur- 
rent and  it  is  not  so  readily  put  out  of  service 
by  dampness  and  dirt.  On  the  other  hand, 
good  contacts  are  required  all  through  the 
system,  and  particularly  the  contacts  within 
the  cylinder  must  be  kept  clean.  This  is  diffi- 
cult, for  there  is  a  continual  deposit  of  soot  and 
oil.  Mechanically,  the  system  is  defective  be- 
cause of  the  numerous  moving  parts  and  wear- 
ing surfaces. 

The  jump  spark  design  is  that  in  which  a 
spark  plug  is  used  in  the  engine  cylinders. 
Here  the  spark  points  are  stationary  (but  ad- 
justable) with  a  fixed  distance  between  them. 
They  are  in  circuit  with  the  secondary  of  an  in- 
duction coil,  commonly  referred  to  as  a  jump 
spark  coil  or  a  vibrating  coil.  It  consists  of 
two  windings.  The  primary  has  a  few  turns  of 
comparatively  large  copper  wire  and  is  con- 
nected to  the  battery.  The  secondary  has  many 
thousands  of  turns  of  fine  wire,  the'  fine  wire 
being  used  solely  to  allow  the  coils  to  be  crowded 
close  to  the  core  and  to  save  space  and  cost. 


114  FARM   ENGINEERING 

Owing  to  the  larger  number  of  turns  in  the 
secondary,  the  voltage  or  "pressure"  of  that 
circuit  is  higher  than  that  of  the  battery  circuit, 
and  so  it  can  force  a  flow  of  electricity  across  the 
gap.  The  current  flowing  in  the  secondary  is 
less  than  that  in  the  primary,  and  it  cannot  be 
measured  easily  and  directly  by  convenient 
instruments.  The  current  in  the  primary,  how- 
ever, may  be  measured  by  means  of  a  pocket 
battery  ammeter,  and  should  not  exceed  one 
fourth  or  one  half  an  ampere  if  the  circuit  is 
in  proper  condition. 

The  principal  disadvantage  is  the  high 
tension  or  voltage  used,  because  of  the  difficulty 
with  which  proper  insulation  is  obtained.  The 
least  dirt  or  moisture  is  fatal  to  the  workings 
of  the  system.  The  vibrator  in  the  primary 
circuit  used  to  rapidly  open  and  close  the  circuit 
is  many  times  the  source  of  much  annoyance. 
On  the  whole,  however,  this  system  is  most 
generally  adopted  for  medium  and  small  sized 
engines. 

Magnetos  are  common  in  ignition  systems, 
the  low  tension  replacing  the  battery  in  the 
make  and  break  systems  and,  occasionally,  in 
the  primary  of  the  jump  spark  design.     The 


THE    IGNITION    SYSTEM 


us 


high-tension  magneto,  when  used,  takes  the 
place  of  the  whole  jump  spark  system  if  desired, 
the  spark  plug  being  connected  directly  to  it. 
In  all  of  these  systems  the  electrical  action  is 
practically  instantaneous,  but  it  is  not  always 
realized  that,  although  combustion  in  the  en- 
gine cylinder  is  extremely  rapid,  there  is  a  defi- 
nite period  of  time  which  occurs  between  the 
closing  of  the  electrical  circuit  and  the  point 
of  maximum  pressure  set  up  by  the  explosion  of 
the  gases.  Such  is  the  case,  however,  the  exact 
time  depending  upon  the  proportions  of  air  and 
oil  vapour  in  the  mixture,  as  shown  by  the 
following  table  of  approximate  combustion  pe- 
riods: 

TABLE   OF   COMBUSTION    PERIODS 


Time  of  combustion 

Mixture  proportions 

in  seconds 

I  part  gas  to  4  parts  air 

O.O4 

1  part  gas  to  7  parts  air 

O.O8 

1  part  gas  to  9  parts  air 

O.I2 

1  part  gas  to  11  parts  air 

O.I8 

1  part  gas  to  12  parts  air 

O.23 

1  part  gas  to  13  parts  air 

0.28 

1  part  gas  to  14  parts  air 

O.3I 

Because  of  this  slowness  of  combustion,  the 
spark  circuit  must  be  closed  a  little  while  before 


Il6  FARM    ENGINEERING 

the  piston  gets  to  the  exact  point  where  it  is 
desired  that  explosion  take  place.  Sometimes, 
for  example,  the  spark  circuit  is  closed  before  the 
piston  reaches  the  end  of  its  compression  stroke. 
Yet,  at  the  same  time,  the  force  of  the  explosion 
does  not  occur  until  after  the  maximum  compres- 
sion has  taken  place  and  the  piston  started  back. 
There  are,  particularly  with  automobile  en- 
gines, many  changes  from  time  to  time  in  the 
richness  of  the  mixture,  and  so,  of  course,  there 
must  be  changes  in  the  point  of  ignition  because 
there  will  not  be  the  same  intervals  between 
closing  the  sparking  circuit  and  the  point  of 
complete  combustion.  This  variation  in  the  mix- 
ture is  due  to  changing  the  throttle,  opening  and 
closing  it  from  time  to  time  as  the  load  varies. 
Then,  too,  with  an  increase  in  the  speed  of  the 
engine  the  spark  must  be  advanced  because 
the  circuit  must  be  closed  earlier  in  the  stroke  to 
allow  the  same  period  of  time  to  elapse  before 
the  piston  reaches  the  end  of  stroke,  the  piston 
travelling  so  much  faster  than  before.  On  the 
other  hand,  if  the  engine  is  being  started,  the 
piston  is  travelling  slowly  and  so  the  spark  must 
be  retarded.  That  is,  the  circuit  must  be 
closed  at  the  time  when  the  piston  is  at  the  end 


THE    IGNITION    SYSTEM  1 17 

of  the  stroke,  or  after  it  has  passed  the  end  of 
stroke,  usually  the  latter.  In  either  case  the 
maximum  force  of  the  explosion  will  occur  after 
the  piston  has  started  back.  Care  should  be 
taken  that  explosion  shall  not  occur  when  the 
piston  is  exactly  at  the  end  of  stroke,  because 
that  causes  bad  knocking  owing  to  the  full  force 
of  explosion  being  transmitted  directly  to  the 
crank  and  crank-shaft  bearings. 

If  explosion  occurs  before  the  piston  reaches 
the  end  of  stroke  when  the  engine  is  starting,  it 
may  reverse  the  direction  of  motion  of  the  crank 
and  so  injure  the  operator  who  is  trying  to  turn 
it  over  the  other  way.  If  the  explosion  occurs 
too  early,  when  the  engine  is  running,  there  will 
be  a  loss  of  power  because  the  force  of  the  ex- 
plosion will  oppose  the  motion  of  the  piston. 
Then,  too,  combustion  is  slower  with  the  gas 
under  less  pressure,  so  that  the  engine  will  be- 
come overheated  if  running  continually  with  a 
much  retarded  spark. 

These  facts  underlie  three  rules  of  spark  con- 
trol which  should  be  memorized  and  under- 
stood by  every  engine  operator: 

i.  Always  retard  the  spark  before  starting 
the  engine. 


Il8  FARM    ENGINEERING 

2.  Always  advance  the  spark  as  the  engine 
picks  up  speed. 

3.  Always  retard  the  spark  when  the  engine 
slows  down  under  a  heavy  load. 

In  every  case  when  the  engine  is  running,  the 
object  of  spark  control  is  to  get  an  explosion  at 
the  moment  when  the  crank  has  passed  the 
dead  centre  and  the  piston  has  started  back  on 
the  return  stroke.  This  will  give  the  maxi- 
mum power  and  the  most  economical  operation. 
An  explosion  at  any  other  time  in  the  stroke 
wastes  fuel  and  injures  the  engine — from  undue 
strain  if  before  the  piston  reaches  the  end  of 
stroke,  and  from  overheating  if  after. 


CHAPTER   XVII 

Determining  the  Horsepower  of  an 
Engine 

There  are  two  values  which  are  known  as  the 
horsepowers  of  any  engine.  One  is  called  "in- 
dicated horsepower,"  and  usually  written  I.  H. 
P.,  while  the  other  is  the  "brake  horsepower," 
written  B.  H.  P.  The  indicated  horsepower  of 
a  steam  engine  is  the  mechanical  work  done  in  a 
certain  time  by  the  steam  acting  on  the  piston. 
Some  of  that  work  goes  to  run  the  engine  itself, 
overcoming  the  friction  of  the  bearings  and  the 
drag  of  the  moving  parts,  so  that  only  a  portion 
of  the  force  exerted  can  be  delivered  to  the  belt 
pulley.  The  work  which  can  be  done  by  this 
portion  at  the  pulley,  in  a  certain  length  of  time, 
is  the  brake  horsepower. 

To  understand  fully  the  methods  of  measure- 
ment of  these  values,  we  must  understand  the 
terms  work,  power,  and  energy  as  they  are  used 
in   engineering.     Any   force   which   is   exerted 

119 


120  FARM    ENGINEERING 

through  a  distance  is  said  to  do  work.  For  ex- 
ample, an  iron  weight  which  drops  from  a  height 
of  two  feet  does  work,  because  the  force  of  grav- 
ity equal  to  the  weight  of  the  iron  is  exerted 
through  two  feet.  The  amount  of  work  done  is  the 
product  of  the  force  in  pounds  and  the  distance 
in  feet.  The  unit  used  is  the  foot-pound.  If,  then, 
the  iron  above  mentioned  weighs  ten  pounds 
the  work  done  when  it  falls  two  feet  is  the 
product  of  ten  and  two,  that  is,  twenty  foot- 
pounds. Work  is  the  product  of  force  and 
distance. 

Energy  is  the  ability  to  do  work.  It  is  the 
capacity  for  work  that  a  body  or  substance  has, 
and  is  measured  in  foot-pounds  just  the  same 
as  work.  The  weight  mentioned,  before  it  fell, 
had  the  ability  to  fall  and  do  twenty  foot- 
pounds of  work.  Thus  we  say  that  it  pos- 
sessed twenty  foot-pounds  of  energy. 

Power  is  the  rate  of  doing  work.  If  an 
engine  can  do  33,000  foot-pounds  of  work  in  one 
minute,  it  is  a  one-horsepower  engine,  that 
figure  being  the  standard  chosen  to  represent  a 
horsepower.  Power  has  to  do  with  time.  Any 
engine  can  do  33,000  foot-pounds  of  work, 
even  a  toy  engine  if  you  give  it  time  enough. 


HORSEPOWER   OF   AN    ENGINE 


121 


The  point  to  be  noticed  is  that   a  one-horse- 
power engine  must  be  able  to  do  that  much  work 


Fig.  26. — The  engine  indicator 

in  one  minute.     A  two-horsepower  engine  must 
do  that  amount  in  half  a  minute,  or,  what  is 


122  FARM    ENGINEERING 

the  same  thing,  it  must  do  twice  that  amount 
in  one  minute. 

To  measure  the  indicated  horsepower  of  a 
steam  or  oil  engine,  an  instrument  known  as 
the  indicator  is  used.  The  illustration  shows 
the  general  appearance  of  the  indicator  used 
with  steam  engines,  and  the  same  general 
arrangement  is  found  in  all  indicators.  There 
is  a  cylinder  to  which  steam  is  admitted  from 
the  engine  cylinder.  The  steam  forces  the 
piston  back  against  the  resistance  of  a  coiled 
spring  which  has  been  experimented  with  previ- 
ously, so  that  the  pressure  exerted  by  the  steam 
on  the  little  piston  is  known  from  the  amount 
the  spring  is  compressed.  As  the  area  of  the 
small  piston  is  usually  just  one  square  inch,  the 
pressure  indicated  by  the  compression  of  the 
spring  is  the  pressure  per  square  inch  of  the 
engine  piston.  So  if  we  multiply  this  indicated 
pressure  by  the  total  area  of  the  engine  piston, 
the  result  obtained  is  the  total  steam  pressure  on 
the  engine  piston.  This  varies  continually  on 
account  of  the  movement  of  the  piston  and  the 
expansion  of  the  steam. 

There  is  also  on  the  indicator  a  rotating  drum 
which  turns  through  a  distance  proportional  to 


HORSEPOWER   OF  AN    ENGINE  I23 

the  stroke  of  the  engine  piston.  A  pencil  is  so 
arranged  that  it  goes  up  and  down  with  the  in- 
dicator piston,  and  as  the  drum  rotates  be- 
neath the  pencil  the  latter  draws  a  diagram 
with  its  length  proportional  to  the  engine  stroke 
and  its  height  proportional  to  the  pressure  on 
the  engine  piston.     The  accompanying  figure 


£/tSINE  STROKE 

Fig.  27. — A  typical  indicator  card.  A  is  the  point  where  the 
steam  is  cut  off,  B  the  point  where  the  exhaust  is  opened,  C 
is  where  compression  begins,  and  D  is  where  admission  of  live 
steam  starts,  the  pressure  rapidly  running  up  to  live  steam  pres- 
sure at  E 

shows  the  shape  of  such  a  diagram,  and  this  is 
known  as  an  indicator  diagram.  Mathematical 
calculations  show  that  the  area  of  such  a  dia- 
gram as  this  is  proportional  to  the  product  of 
the  average  pressure  on  the  piston  during  the 
stroke  and  the  length  of  the  stroke.  In  other 
words,  the  area  of  this  diagram  is  proportional 


124 


FARM    ENGINEERING 


to  the  work  done  on  the  piston  of  the  engine 
by  the  steam  during  one  stroke,  so  that  know- 
ing the  number  of  strokes  per  minute  made  by 
the  engine  piston  we  may  easily  find  the  work 
done  per  minute.  This  divided  by  33,000  gives 
us  the  indicated  horsepower  (I.  H.  P.)  of  the 
engine,  because  33,000  foot-pounds  per  minute 
equals  one  horsepower. 

jm    J    -l, 


S 


Z=) 


Fig.  28. — One  form  of  prony  brake 

To  measure  the  brake  horsepower  of  any  en- 
gine, an  instrument  known  as  the  prony  brake  or, 
more  technically,  the  absorption  dynamometer, 
is  used.  This,  as  shown  in  the  drawing,  con- 
sists of  a  band  which  may  be  tightened  around 
the  engine  pulley,  creating  great  friction  on  the 
pulley  and  requiring  constant  force  acting  to 
overcome  this  friction.     As  this  force  is  acting 


HORSEPOWER   OF   AN    ENGINE  I25 

constantly  on  the  rim  of  the  pulley,  in  one  revo- 
lution of  the  pulley  the  force  acts  through  a 
distance  equal  to  the  circumference  of  the 
pulley.  The  circumference  is  three  and  one 
seventh  times  the  diameter.  The  product  of 
the  length  of  the  circumference  and  the  force  of 
friction  acting  will  give  the  work  done  in  one 
revolution.  Then  by  counting  the  number  of 
revolutions  per  minute  and  multiplying  this 
number  by  the  work  done  in  one  revolution  and 
dividing  by  33,000  we  get  the  brake  horsepower. 
It  is  difficult  to  measure  the  force  of  friction 
directly,  so  that  it  is  measured  by  suspending 
weights  on  the  end  of  a  long  arm  as  shown  in 
the  figure.  By  the  principle  of  the  lever,  the 
force  acting  at  the  circumference  of  the  wheel 
is  to  the  force  exerted  by  the  weights  at  the  end 
of  the  arm  as  the  length  of  the  arm  measured 
from  the  centre  of  the  shaft  is  to  the  radius  of 
the  wheel  or  pulley.     That  is: 

Friction  force  Length  of  arm 


Weights  Radius 

and  hence 

Length  of  arm  X  weights 
Friction  force    =    — 


Radius  of  pulley 


126  FARM    ENGINEERING 

And  the  horsepower  as  stated  above,  being 
friction  force  times  the  circumference  times  the 
number  of  revolutions  per  minute  (written  R.  P. 
M.)  divided  by  33,000  will  give  the  following 
value  for  B.  H.  P.  by  substituting  the  value  of 
the  friction  force  found  above : 

Length  of  arm  x  weights  X  3I  x  pulley  diam.  x  R.P.M 

B.H.P.= ; 

Radius  of  wheel  X  33,000 

Length  of  arm  X  weights  x  3$  X  2  X  R.P.M. 
33,000 

because  the  diameter  is  twice  the  radius  and  we 
may  divide  them. 

If  now  we  take  pains  to  have  the  length  of 
the  arm  measured  from  the  engine  shaft  to  the 
weights,  just  3!  feet  long,  the  formula  becomes 
simplified  and  we  obtain,  by  dividing 

Weights  x  R.P.M. 
B.H.P.  = 


1,500 


The  belt  which  creates  the  friction  is  usually 
made  of  heavy  canvas  held  by  springs  at  one  end 
while  a  turnbuckle  is  used  at  the  other  end  in 
order  that  the  belt  may  be  tightened  at  will  and 


HORSEPOWER   OF   AN    ENGINE  I27 

the  force  of  friction  increased.  In  long-continued 
tests  it  is  frequently  found  necessary  to  throw 
water  over  the  belt  and  pulley  to  keep  them  cool. 
In  place  of  the  weights  a  spring  balance  may  be 
used,  care  being  taken  that  the  turning  direction 
of  the  pulley  is  such  as  to  pull  against  the  bal- 
ance. With  small  engines,  up  to  ten  or  twelve 
horsepower,  a  balance  reading  to  twenty-five 
pounds  is  large  enough. 

Gasoline  and  other  oil  engines  for  farm  use 
are  usually  rated  at  their  tested  brake  horse- 
power, but  the  power  of  steam  engines,  un- 
fortunately, is  not  so  accurately  stated.  The 
commercial  power  rating  of  steam  engines  is 
ordinarily  only  one  half  or  one  third  of  what 
they  actually  will  do  under  test.  The  custom 
in  making  calculations  is  to  assume  that  a  steam 
engine  of  any  specified  rating  will  give  the  same 
power  as  a  gasoline  engine  of  twice  the  rating. 

The  rating  of  a  steam  boiler  in  boiler  horse- 
power has  nothing  whatever  to  do  with  the  unit 
of  power  we  have  been  using.  A  boiler  horse- 
power and  an  engine  horsepower  bear  no 
definite  relation  to  each  other.  A  boiler  horse- 
power is  defined  as  equivalent  to  the  evaporation 
of  thirty-four  and  one  half  pounds  of  water  per 


128  FARM    ENGINEERING 

hour  from  water  at  212  degrees  Fahrenheit  to 
steam  at  the  same  temperature  and  at  the 
pressure  of  the  atmosphere.  Under  ordinary 
conditions  with  farm  engines,  one  boiler  horse- 
power will  furnish  sufficient  steam  to  operate 
an  engine  of  about  one  half  horsepower  ca- 
pacity. This,  however,  is  only  an  approxi- 
mation. 


CHAPTER  XVIII 
Utilizing  Small  Streams  for  Power 

The  idea  of  water  power  is  generally  as- 
sociated with  a  mental  picture  of  an  expensive 
installation  which  is  beyond  the  purse  of  most 
farmers,  yet  it  is  no  exaggeration  to  say  that  on 
many  farms  small  streams  could  be  harnessed 
to  do  the  work  required  of  an  engine  and  with 
very  little  expense.  The  size  of  the  stream  and 
the  amount  of  fall  is  of  first  interest,  of  course, 
in  order  that  calculations  may  be  made  of  the 
possible  amount  of  power  which  can  be  gene- 
rated. To  understand  how  these  calculations  are 
made  we  must  first  find  out  just  what  is  meant 
by  "horsepower."  This  is  discussed  quite 
fully  in  Chapter  XVII,  and  again  in  connection 
with  Table  VII.  Power  is  defined  as  the  rate 
of  doing  work,  and  the  unit  of  power  is  taken  as 
33,000  foot-pounds  of  work  done  in  one  minute. 

To  find  the  maximum  possible  power  which 
can  be  obtained  from  a  falling  body  of  water, 

129 


% 


I30  FARM    ENGINEERING 

then,  it  is  only  necessary  to  determine  the  weight 
of  water  which  falls  in  one  minute  and  the 
distance  that  this  water  falls.  The  latter 
distance,  as  a  rule,  may  be  easily  measured. 
If  the  weight  of  the  water  is  desired,  the  first 
step  is  to  determine  the  quantity  of  water  fall- 
ing in  one  minute,  usually  in  cubic  feet.  This 
quantity  is  obtained  by  multiplying  the  average 
depth  in  feet  by  the  average  width  in  feet  and 
multiplying  their  product  by  the  velocity  of 
flow  in  feet  per  minute.  It  will  assist  the  cal- 
culation greatly  if  a  stretch  of  stream  is  taken 
which  does  not  vary  greatly  in  width.  Say 
the  stretch  is  200  feet  long.  Measure  the 
width  of  the  stream  at,  say,  ten  places  along 
this  stretch.  At  each  place  take  six  measure- 
ments of  the  depth  of  the  stream,  spacing  the 
measurements  from  shore  to  shore.  Average 
the  six  measurements  and  multiply  by  the  width 
at  that  place,  getting  the  cross-section  at  each 
place.  Average  these  cross-sections  and  multi- 
ply by  the  average  velocity  of  the  stream. 
The  latter  may  be  obtained  by  noting  the  time 
taken  for  a  chip  to  float  the  stretch  of  200  feet; 
or  perhaps  an  easier  method  would  be  to  note 
how  far  a  chip  will  float  over  this  course  in  one 


UTILIZING    SMALL    STREAMS    FOR    POWER    131 

minute.  The  final  result  will  be  in  cubic  feet, 
and,  as  a  cubic  foot  of  water  weighs  62.4 
(Table  III)  pounds,  multiplying  by  this  figure 
will  give  the  weight  of  water  which  falls  in  one 
minute  at  any  part  of  the  stream.  Multiply 
this  weight  by  the  distance  fallen  through  and 
divide  by  33,000  to  get  the  maximum  theoreti- 
cal horsepower.  As  stated  in  the  chapter  and 
table  previously  referred  to,  this  maximum 
horsepower  cannot  be  obtained  from  any  com- 
mercial wheels,  their  efficiencies  ranging  from 
50  to  85  per  cent.,  as  pointed  out  in  Table  II. 

The  term  "miner's  inch,"  which  is  some- 
times met  with  in  waterpower  apparatus  cata- 
logues, is  a  California  term  and  is  really  quite 
indefinite  in  its  meaning,  the  exact  amount 
meant  depending  upon  the  particular  locality 
where  the  term  is  used.  An  average  value  for 
the  miner's  inch  is  one  and  one  half  cubic  feet 
of  water  per  minute.  The  number  of  miner's 
inches  in  any  stream,  then,  may  be  approxi- 
mately determined  by  dividing  the  stream  flow 
in  cubic  feet  per  minute  by  one  and  one  half. 

If  the  water  to  be  utilized  is  from  a  small 
waterfall,  the  calculations  may  be  made  in  the 
stream  above  the  fall.     If  necessary  or  desirable 


132 


FARM    ENGINEERING 


the  stream  might  be  led  through  an  open 
wooden  channel  of  known  cross-section  and 
known  length.  The  width  of  the  box  will  give 
the  width  of  the  stream.  The  depth  of  the 
stream  can  be  measured  by  means  of  a  rule  held 
upright  with  the  end  resting  on  the  bottom  of 
the  box.  The  velocity  can  be  determined  from 
the  time  taken  for  a  chip  to  float  the  known 
length  of  the  open  box. 

The  following  table  gives  the  number  of 
cubic  feet  which  must  fall  per  minute  to  give 
one  horsepower  under  the  various  heads  named: 


WATER  REQUIRED   TO   GIVE    ONE    HORSEPOWER 


Head  in  feet 


Cubic  feet  per  minute 
required 


5 
10 

IS 

20 

30 

35 
40 


105.6 
52.8 
35-2 
26.4 

21. 1 

17.6 

I5-I 

13.2 


Knowing  the  horsepower  which  it  is  possible 
to  develop,  the  next  thing  is  to  choose  the  type 
of  wheel.  In  general,  water-wheels  may  be 
classified  as  gravity,  impulse,  or  reaction  wheels. 


UTILIZING    SMALL    STREAMS    FOR    POWER     1 33 

The  gravity  type  are  operated  directly  by  the 
weight  of  the  falling  water  exerted  through  its 
falling  distance.     Such  are  the  breast  and  over- 


SntAST 


TCLTOlt 


Fig.  29. — Types  of  water-wheels 


134  FARM    ENGINEERING 

shot  wheels  represented  diagrammatically  in 
Fig.  29.  They  are  used  solely  in  small  plants, 
being  inefficient  under  normal  conditions.  Un- 
der the  best  conditions  the  efficiency  of  the 
breast  wheel  ranges  from  55  to  65  per  cent.,  and 
that  of  the  overshot  from  65  to  75  per  cent. 
If  the  fall  in  the  stream  is  but  a  few  feet 
the  breast  wheel  is  quite  generally  used.  A 
slightly  greater  fall,  say  six  to  eight  feet, 
usually  results  in  the  choice  of  an  overshot. 
These  gravity  wheels  are  advocated  for  slight 
falls  of  from  three  to  eight  feet,  or  thereabouts, 
for  small  installations  largely  because  of  the 
fact  that  small  turbines  for  slight  falls  are  apt 
to  be  of  low  grade  materials  and  poor  design. 
The  gravity  wheels  are  much  easier  to  make  and 
install.  In  fact,  overshot  wheels  are  frequently 
constructed  by  the  farmer  himself.  It  may  be 
any  form  of  wheel  with  buckets  or  paddles  on 
the  circumference  so  that  water  will  be  retained 
until  it  has  reached  the  lowest  point,  and  the 
weight  of  the  water  thus  impart  a  turning 
motion  to  the  wheel.  Even  board  wheels  of 
rough  design  and  construction  will  give  con- 
siderable power. 

Impulse  wheels  are  those  in  which  the  total 


UTILIZING    SMALL    STREAMS    FOR    POWER     I35 

energy  of  the  wheel  is  obtained  from  the  move- 
ment or  velocity  of  the  running  water.  The 
undershot  wheel  represented  and  the  Pelton 
wheel  are  examples  of  this  class.  While  the 
undershot  wheel  is  perhaps  the  least  efficient 
of  all  water-wheels,  averaging  from  25  to 
45  per  cent,  under  good  conditions,  the  Pel- 
ton  is  the  most  efficient.  Under  favourable 
conditions  the  efficiency  of  the  latter  reaches 
85  per  cent.,  and  in  all  intelligent  installations 
it  runs  well  over  75  per  cent.  A  running  stream 
having  a  slight  fall  furnishes  opportunity 
for  the  common  mill  wheel  of  the  undershot 
type.  Where  it  is  used  the  stream  is  narrowed 
to  about  the  width  of  the  wheel,  thus  giv- 
ing the  wheel  the  benefit  of  all  the  water  in 
the  stream  running  at  a  somewhat  greater 
velocity  than  in  the  open  stream.  This  type  is 
rapidly  disappearing  altogether,  and  is  not  to  be 
recommended  if  other  types  may  be  installed. 
Frequently  in  order  to  use  another  type  as,  for 
example,  the  breast  wheel,  a  dam  would  have  to 
be  constructed  to  get  a  sufficient  fall  of  water. 
There  is  a  low  breast  wheel  which  is  sort  of  a 
cross  between  the  breast  and  the  undershot. 
This  is  used  where  the  fall  is  slight,  say  a  foot  or 


I36  FARM    ENGINEERING 

two.  The  water  is  delivered  to  some  point  of 
the  wheel  below  the  shaft,  anywhere  between 
one  quarter  and  three  quarters  of  the  distance 
from  lower  point  to  shaft. 

The  Pelton  wheel  is  increasing  in  use,  and  to- 
gether with  the  turbine  is  universally  installed  in 
plants  of  any  size.  For  all  heads  above  eight  or 
ten  feet  this  wheel  equals  the  turbine  in  efficiency. 
For  heads  less  than  twenty  to  twenty-five  feet, 
however,  the  amount  of  water  used  by  the 
Pelton  makes  the  turbine  somewhat  more  eco- 
nomical. Above  twenty  feet  there  is  little  choice 
from  efficiency  or  cost  of  operation  until  high 
heads  of  from  100  to  2,000  feet  are  reached. 
With  these  there  can  be  little  choice  between 
the  two,  the  Pelton  being  greatly  superior. 
The  principle  of  operation  makes  a  high  head 
desirable  with  the  Pelton  wheel.  The  higher 
the  head  the  less  the  amount  of  water  required 
to  develop  a  given  power.  Hence,  the  lower 
the  cost  of  installation,  for  provision  need  be 
made  to  convey  only  a  slight  amount  of  water. 
The  power  of  a  Pelton  wheel  depends  solely 
upon  the  head  and  the  amount  of  water  supplied 
to  the  wheel.  The  diameter  of  the  wheel  merely 
determines  the  speed  at  which  it  runs,  and  to 


UTILIZING    SMALL    STREAMS    FOR    POWER     1 37 

some  extent  is  dependent  upon  mechanical 
considerations.  With  great  quantities  of  water 
flowing  from  the  nozzle,  the  buckets  against 
which  the  water  strikes  must  be  large  enough 
for  the  full  benefit  of  the  issuing  stream,  and  thus 
the  wheel  must  be  large  enough  to  carry  the 
buckets.  Most  of  the  so-called  water  motors 
are  of  the  Pelton  type.  They  range  in  price 
from  $30  for  the  little  six-inch  motor,  weighing 
fifty  pounds,  up  to  #275  for  the  twenty-inch 
size,  weighing  860  pounds.  Smaller  motors  down 
to  about  one  eighth  horsepower  may  be  bought 
for  as  low  as  #10. 

Turbines  are  of  the  reaction  class  of  wheels, 
the  reaction  of  the  water  as  it  leaves  the  vanes 
furnishing  the  "kick"  which  propels  the  wheel. 
In  this  type  of  wheel,  in  distinction  from  all 
others  shown,  the  water  acts  around  the  entire 
circumference  at  once.  The  efficiency  depends 
largely  upon  the  design  and  the  carefulness  of 
installation.  It  may  be  anywhere  from  55  per 
cent,  up  to  85  per  cent.  It  is  best  adapted  for 
low  and  moderate  heads,  especially  where  the 
head  varies  greatly  from  time  to  time.  It 
operates  at  higher  speeds  than  the  other 
wheels,  and  will  perform  its  work  even  if  set 


i38 


FARM    ENGINEERING 


below  the  level  of  the  water  in  the  tail-race. 
Low  heads  and  large  quantities  of  water  cause 
the  adoption  of  the  turbine. 

A  preliminary  survey  and  outline  report  by  a 
competent  engineer  is  advisable  in  every  case 
where  a  waterpower  plant  of  any  great  size  is 
to  be  erected.     Such   advice  is  not  expensive 


sent*  ruas/\£ 


^m 


t/ONVAl   TVPSINE 


Fig.  30. — Diagrammatic  representation  of  typical  turbine  wheels 

and  will  many  times  set  the  farmer  on  the  right 
track  regarding  details  of  his  venture.  For 
small  installations,  however,  the  farmer  may 
rely  on  his  own  judgment  and  the  help  available 
from  the  manufacturer  from  whom  he  pur- 
chases the  wheel.     This  chapter  is  written  for 


UTILIZING    SMALL    STREAMS    FOR   POWER     1 39 

the  purpose  of  calling  attention  to  the  possi- 
bilities of  the  small  stream  running  through  the 
fields,  and  pointing  out  a  method  by  which  the 
farmer  may  calculate  for  himself  the  power 
available  and  the  kind  of  wheel  to  install.  Just 
what  installation  is  best  in  each  case  and  the 
exact  cost  depend  upon  local  conditions.  Be- 
fore determining  the  size  of  wheel  to  use,  the 
condition  of  the  stream  at  all  seasons  of  the 
year  must  be  taken  into  account.  The  in- 
stallation is  for  continuous  use  and  average 
conditions  must  be  figured  on,  for  if  the  head  of 
water  is  real  variable  a  wheel  too  large  for  all 
but  the  highest  heads  will  operate  at  a  very  low 
efficiency  when  the  head  is  low.  On  the  other 
hand,  a  wheel  too  small  for  any  but  the  very 
low  heads  will  have  a  low  efficiency  on  the  high 
heads.  In  almost  every  case  the  wheel  is  chosen 
to  run  at  a  certain  fixed  speed.  This  speed 
cannot  be  maintained  under  wide  variations  in 
head  without  affecting  the  efficiency  of  the 
plant.  The  usual  solution  is  to  arrange  the 
plant  so  that  the  head  will  remain  as  nearly 
constant  as  possible  and  any  surplus  water  go 
to  waste.  As  has  been  stated,  low  heads  are 
best  developed  by  turbines  and  high  heads  by 


140 


FARM    ENGINEERING 


Pelton  wheels.  These  two  types  are  practi- 
cally the  only  ones  which  can  be  purchased  for 
small  installations.  The  other  types,  however, 
are  quite  readily  built  by  an  intelligent  farmer. 


Fig.  31. — General  location  of  dam  and  turbine  wheel  in  most 
installations 

For  turbine  installations  the  natural  head  at 
a  fall  is  usually  enlarged  by  building  a  dam 
across  the  stream  at  that  point.  Off  to  one  side 
of  the  dam,  as  shown  in  Fig.  31,  the  raised  water 


UTILIZING    SMALL    STREAMS    FOR    POWER     I4I 

enters  the  head-race,  goes  through  the  turbine, 
and  then  goes  out  through  the  tail-race.  The 
short  length  of  pipe  or  open  channel  from  the 
head-race  to  the  wheel  is  called  the  penstock  or 
flume.  The  portion  of  the  watercourse  in  which 
the  wheel  is  situated  is  called  the  wheel  pit. 
The  following  table  gives  some  figures  about 
successful  farm  installations  of  waterpower  in 
various  parts  of  the  country.  All  of  these  are 
turbine  plants. 

FARM   WATERPOWER   PLANTS 


Head  of  water 

Power  developed 

Length  of  dam 

Cost  of  plant 

6  feet 

II  " 

IS    " 

17  - 

17  h.p. 
8     " 
5     " 

15     " 

36  feet 
3SO 
(used  old  dam) 
200  feet 

$1,000 

I,000 

225 

700 

The  costs  are  given  merely  for  the  power 
plant  and  do  not  include  cost  of  transmission 
lines  from  plant  to  the  place  where  the  power 
was  used  for  electric  lighting,  etc.,  nor  do  they  in- 
clude the  cost  of  wiring  the  buildings  lighted. 
All  this  depends,  of  course,  on  particular  con- 
ditions which  vary  greatly  in  every  installation. 
These  four  cases  serve  to  indicate  the  possible 
variation  in  cost  of  the  power  plant  itself  for 


142  FARM    ENGINEERING 

even  approximately  the  same  power.  In  al- 
most every  case  an  estimate  of  #50  per  horse- 
power will  cover  the  cost  of  the  plant  alone,  and 
from  #75  to  #100  per  horsepower  will  cover  the 
cost  of  the  entire  installation  including  wiring, 
lights,  motors,  etc.  The  higher  the  head  the  less 
the  cost,  other  things  being  the  same.  The 
larger  the  plant  the  less  the  cost  per  horsepower 
usually. 

In  the  table  given  above,  the  dam  in  the 
eight-horsepower  plant  was  of  earth.  It  cost 
about  #400.  In  the  fifteen-horsepower  instal- 
lation the  dam  was  of  concrete  and  raised  the 
available  head  50  per  cent,  to  the  figure  given. 
The  cost  of  operation  is  merely  the  interest  and 
depreciation  on  the  plant  and  the  taxes  amount- 
ing to  approximately  #8  per  month.  The 
actual  cash  outlay  for  oil  and  repairs  will  not 
exceed  $1.25  a  month.  That  is,  for  less  than 
$10  per  month  this  man  has  fifteen  horsepower 
available  for  his  service  night  and  day  con- 
tinually. While  the  first  cost  is  somewhat 
greater  than  that  of  a  fifteen-horsepower  oil 
engine,  the  latter  would  cost  at  least  $50  per 
month  for  continual  operation. 

The  turbine  wheel  must  be  installed  pretty 


UTILIZING    SMALL    STREAMS    FOR    POWER     I43 

close  to  the  dam,  but  the  Pelton  wheel  is  fre- 
quently far  from  the  point  where  the  water  is 
available.  In  the  first  case  the  power  used  is 
transmitted  electrically  from  the  power  house 
at  the  stream  to  the  place  where  it  is  to  be  used. 
In  the  latter  case  the  water  is  transmitted  from 
the  stream  through  pipes  to  the  Pelton  wheel. 
As  a  rule  there  is  no  dam  or  similar  construction 
necessary  if  a  Pelton  wheel  is  used.  In  fact, 
there  need  be  no  running  water.  A  pond 
elevated  above  the  wheel  is  ideal.  The  ex- 
pense consists  of  the  pipe  line  to  the  wheel,  the 
wheel  itself,  the  drain  or  other  arrangement  to 
carry  the  waste  water  away.  This  style  of 
plant  lends  itself  to  ready  use  in  connection 
with  irrigation  projects.  Under  these  circum- 
stances the  water  is  brought  to  the  wheel,  and 
after  leaving  it  the  waste  water  is  led  away  to 
the  fields  to  be  irrigated.  The  expense  incurred 
may  then  be  divided  between  the  two  projects, 
power  and  irrigation,  and  the  total  expense  for 
both  will  but  slightly  exceed  that  for  either 
alone. 

The  cost  of  the  Pelton  wheel  depends  upon 
the  size.  Depending  upon  the  head  under 
which  it  is  to  operate,  a  three-foot  wheel  costs 


144 


FARM    ENGINEERING 


from  $220  to  $450,  a  four-foot  wheel  from  $285 
to  $675,  a  five-foot  wheel  from  $350  to  $625,  a 
six-foot  wheel  from  $400  to  $800.  The  follow- 
ing table  gives  the  horsepower  developed  by 
these  standard  wheels  under  the  various  heads. 
The  amount  of  water  needed  in  each  case  can  be 
figured  by  the  methods  already  given. 


POWER    DEVELOPED    BY    PELTON    WATER-WHEELS 


Head  in  feet 

3-ft.  wheel 
h.p. 

4- ft.  wheel 
h.p. 

5- ft.  wheel 
h.p. 

6- ft.  wheel 
h.p. 

20 

15 

2.6 

4.2 

6.0 

30 

2.8 

4-9 

7  7 

II. O 

40 

4.2 

7.6 

11. 9 

17.0 

50 

6.0 

10.6 

16.6 

23.9 

ICO 

16.8 

29.9 

46.9 

67.4 

ISO 

31.0 

55-0 

86.2 

I24.O 

Smaller  wheels  may  be  purchased  for  smaller 
heads,  or  for  the  same  heads  and  smaller  quan- 
tities of  water  than  required  by  these  large  sizes. 
Any  sized  wheel  can  be  used  on  any  head,  but 
with  a  certain  head  and  a  definite  quantity  of 
water,  a  particular  size  of  wheel  is  best  adapted 
for  the  development  of  the  greatest  power. 


CHAPTER  XIX 
The  Storage  Battery  for  the  Farm 

There  are  only  two  types  of  storage  batteries 
which  can  be  considered  as  valuable  from  a  com- 
mercial standpoint,  but  there  are  many  different 
storage  batteries  which  will  work.  A  storage 
battery  is  merely  any  kind  of  an  electric  battery 
which,  when  charged,  will  be  changed  from  its 
normal  condition  into  a  condition  that  it  cannot 
maintain.  Just  as  a  box  will  stand  up  on  one 
corner  as  long  as  you  steady  it  with  your  hand, 
so  will  the  storage  battery  remain  in  its  un- 
stable condition  so  long  as  it  is  being  charged. 
When  the  charging  current  ceases,  the  battery 
tends  to  return  to  its  original  state,  and  in  doing 
so  it  gives  up  a  portion  of  the  electricity  which 
was  used  in  changing  its  condition  during  charg- 
ing. 

The  storage  battery  does  not  store  up  any- 
thing in  the  sense  that  we  can  store  up  water  in 
a  reservoir.     We  may  compare  the  action  to 

145 


I46  FARM    ENGINEERING 

that  of  the  water  in  a  steam  boiler.  When  the 
fire  under  the  boiler  acts  on  the  water,  it  changes 
the  water  into  the  unstable  form  of  steam.  The 
water  is  charged  with  energy  by  the  heat  of  the 
fire  and  the  steam  is  merely  the  charged  water. 
Now,  if  the  fire  is  withdrawn  from  the  boiler, 
the  steam  will  condense  back  to  the  original 
form  of  water.  Not  all  of  the  heat  which  came 
from  the  fire  will  be  given  up  by  the  steam  when 
it  condenses,  because  much  of  the  fire's  heat 
was  lost  in  radiation  from  the  hot  boiler  con- 
taining the  water  and  steam  and  much  of  it  was 
lost  up  the  chimney.  This  will  never  be  re- 
gained. 

In  the  same  way,  the  electric  storage  battery 
will  not  return  as  much  electricity  as  was  used 
to  charge  it.  One  type,  the  lead-plate  battery, 
will  return  about  80  per  cent.  The  nickel- 
iron  cell  of  Edison  will  return  only  about  60 
per  cent.  In  other  words,  if  you  use  a  storage 
battery  for  your  farm  lighting  plant  and  a 
certain  number  of  charges  cost  you  one  dollar, 
the  electricity  you  get  from  the  battery  on  dis- 
charge is  only  80  cents'  worth  in  one  case  and 
60  cents'  worth  in  the  other.  The  remainder  of 
the  dollar  is  lost  in  operating  the  battery. 


u 


Fig-  35- — lhe  grid  before 
pasting 

Fig-  35-— The  Plante  plate 
after  shredding  but  before 
"  forming  "  the  paste 


Fig.  34.  —  The  pasted  plate 
completed 

Fig.  36. — The  Plante  plate 
completed  and  "formed  " 


STORAGE  BATTERY  FOR  THE  FARM    1 47 

The  lead-plate  storage  battery  consists  of  a 
container,  usually  glass  but  sometimes  rubber, 
a  liquid  chemical  called  sulphuric  acid,  and  two 
plates  holding  a  quantity  of  lead  paste.  The 
plates  may  be  of  two  kinds.  One  variety, 
known  as  pasted  plates,  consists  of  a  grid  or 
framework  made  of  an  alloy  of  lead  and  anti- 
mony with  the  spaces  filled  by  the  lead  paste. 
One  plate,  the  positive,  has  a  paste  of  red  lead 
and  sulphuric  acid,  and  it  is  red  in  colour  or, 
perhaps,  a  reddish  brown.  The  other  plate, 
the  negative,  has  a  paste  of  litharge  and 
sulphuric  acid  and  when  bought  is  usually 
gray. 

The  second  variety  is  known  as  the  Plante 
type.  Plates  of  this  type  consist  of  lead  sheets 
first  cut  up  or  shredded  and  then  treated  with 
acid  over  and  over  again  to  form  the  required 
paste  right  out  of  the  lead  on  the  plate  itself. 
This  is  a  long  process  and  makes  a  more  durable 
but  a  heavier  battery.  It  costs  more  than  a 
battery  using  pasted  plates  and  is  more  desir- 
able. The  chief  trouble  with  the  lighter  pasted 
type  is  that  the  framework  expands  and  lets 
the  paste  fall  out,  thus  ruining  the  battery. 
For  automobiles   and   trucks  where  weight  is 


I48  FARM   ENGINEERING 

important  the  lighter  but  otherwise  less  desir- 
able pasted  plates  are  sometimes  used. 

The  Edison  battery  differs  in  every  way  from 
the  lead  cell.  The  container  in  place  of  being 
glass  is  nickel-plated  steel.  The  plates  in  place 
of  being  the  easily  injured  lead  paste  arrange- 
ments exposed  to  all  kinds  of  abuse  are  nickel 
hydrate  and  iron  oxide  packed  in  strong  steel 
tubes  or  boxes.  The  electrolyte  or  liquid  in 
place  of  being  sulphuric  acid  is  caustic  soda. 

The  particular  advantage  which  is  claimed 
for  the  Edison  cell  is  its  lower  weight  for  the 
same  capacity.  Its  bulk  or  size  does  not  vary 
greatly  from  similar  lead  cells,  and  its  efficiency, 
as  already  stated,  is  considerably  lower.  The 
voltage  or  electrical  pressure  is  but  1.2  volts  as 
against  2.1  volts  for  the  lead  cell,  so  that  for 
work  requiring  a  certain  voltage  as,  say  no 
volts,  nearly  twice  as  many  Edison  cells  will  be 
required,  and  each  Edison  cell  costs  as  much  as 
the  best  type  of  lead  cell.  If  less  weight  were 
its  only  strong  point  it  would  not  be  in  as  great 
demand  as  it  is  for  other  purposes  besides 
electric  vehicles.  The  fact  is  that  its  mechani- 
cal strength  and  dependability  are  enormously 
superior  to  the  lead  cell.     It  may  be  abused  in 


STORAGE    BATTERY   FOR   THE    FARM         I49 

every  way  short  of  absolute  purposeful  de- 
struction with  but  slight  damage  resulting.  This 
is  the  feature  which  commends  it  for  most 
farm  purposes  where  it  must  be  handled  by  men 
who  have  not  been  technically  trained.  It  is 
truly  "as  rugged  as  a  battleship. " 

Whether  or  not  a  storage  battery  should  be 
used  in  connection  with  a  lighting  plant  depends 
largely  on  the  purse  of  the  individual.  A  light- 
ing plant  including  a  storage  battery  must  also 
include  an  engine  and  a  generator  to  charge 
the  battery,  besides  a  switchboard  and  meters. 
Such  a  plant,  even  of  small  size,  will  cost  $300 
or  more,  and  its  efficiency  will  be  very  low.  A 
considerable  decrease  in  first  cost  and  an  in- 
crease in  efficiency  will  be  obtained  if  the  lighting 
circuits  are  connected  directly  to  the  gener- 
ator, no  storage  battery  being  used.  In  this 
case,  of  course,  the  engine  must  run  all  the  time 
lights  are  required.  This  in  some  instances 
will  be  most  inconvenient  unless  there  is  a 
handy  waterfall  or  a  small  stream  to  operate 
the  generator,  but  the  saving  of  #100  or  $150 
first  cost  in  doing  away  with  the  storage  battery 
and  switchboard,  the  saving  of  many  dollars  per 
year  cost  of  upkeep  of  the  battery,  the  saving 


150  FARM    ENGINEERING 

of  its  depreciation,  the  interest  on  the  money 
which  would  have  been  invested  in  it,  and  the 
saving  of  part  of  the  20  per  cent,  loss  on  each 
charge,  will  appeal  to  many  farmers  as  being 
very  desirable  even  at  the  expense  of  some  in- 
convenience. 

The  capacity  and  number  of  cells  to  be  pur- 
chased depend  upon  the  voltage  of  the  system 
installed  and  the  amount  of  lighting  that  is  to 
be  done.  The  voltage  of  the  individual  lead 
cell  is  2.1  when  charged,  but  it  drops  gradually 
to  1.8  volts,  below  which  it  must  not  go.  The 
working  voltage  is  generally  figured  at  2.  The 
Edison  cell,  if  the  discharge  rate  is  normal, 
starts  at  about  1.5  volts  when  fully  charged  and 
drops  very  fast  to  slightly  over  1.2  when  the 
fall  to  0.9  volts  is  gradual.  It  must  not  go 
below  the  latter  figure.  The  normal  voltage 
is  1.2. 

The  capacity  of  a  cell  is  measured  in  ampere- 
hours.  One  ampere-hour  capacity  means  that 
the  cell  will  give  a  current  of  one  ampere  for  one 
hour.  The  cell  will  probably  actually  give  less 
than  one  ampere  if  discharged  in  as  short  a  time 
as  one  hour,  because  the  rating  is  always  at  the 
eight-hour  rate  of  discharge.     That  is,  the  bat- 


STORAGE    BATTERY    FOR   THE    FARM        I5I 

tery  is  rated  to  give  one  eighth  of  an  ampere 
for  eight  hours,  but  if  rushed  to  discharge  in  less 
time  it  will  not  give  quite  its  full  capacity.  The 
eight-hour  rate  is  the  normal  rate. 

A  16-candlepower  20-watt  lamp  requires  two 
thirds  of  an  ampere  at  30  volts,  the  common  house 
voltage  for  these  electric  plants.  At  60  volts  it 
requires  only  half  the  current  to  operate  a  20- 
watt  lamp.  The  "watt"  is  the  electrical  unit 
of  energy.  It  is  the  product  of  one  ampere  and 
one  volt  so,  given  the  watt  rating  of  the  lamp 
and  the  voltage  of  the  system,  divide  the  watts 
by  the  volts  and  you  get  the  amperes  required 
for  a  lamp.  Then  multiply  the  number  of 
lamps  you  wish  to  use  at  one  time  by  the 
number  of  hours  they  must  be  lighted,  and 
multiply  this  by  the  number  of  amperes  for 
one  lamp  under  the  voltage  of  the  system  you 
use  and  you  get  the  ampere-hour  capacity 
required  for  your  storage  battery.  Some  allow- 
ance should  be  made  for  emergencies  which  may 
arise  requiring  the  use  of  more  lamps  than 
usual. 

The  following  table  gives  approximate  ideas 
of  costs  and  capacities  of  some  of  the  battery 
systems: 


152 


FARM   ENGINEERING 
TABLE  I 

STORAGE  BATTERY  SYSTEMS 


<*- 

Number  of  cells 
required 

Approximate  cost  of 
batteries 

Capacity   in    16  c.p. 
tungsten  lamps  for 
5  hours 

o  • 
> 

Lead 

Edison 

Lead 

Edison 

Lead 

Edison 

6 

30 

60 

100 

3 
16 

32 
60 

5 

27 

53 

100 

$    20.70 
IIO.4O 
220.80 
4I4.OO 

$    30.00 
162.OO 
3I8.00 
6OO.OO 

2 
IO 
21 
38 

2 
12 

24 

44 

As  this  table  indicates,  the  cost  of  any  storage 
battery  installation  depends  largely  on  the 
voltage  of  the  system  used.  There  must  be  as 
many  cells  as  the  number  given  by  dividing  the 
voltage  of  the  system  by  the  voltage  of  the  in- 
dividual cell  used.  The  voltages  given  in  the 
table  are  those  usually  used  in  small,  isolated 
country  plants,  the  thirty-volt  system  being 
very  popular.  With  the  higher  voltage  im- 
pressed on  lamps  of  the  same  rating  in  watts 
the  current  consumed  is  less,  of  course,  than 
with  the  lower  voltage,  so  there  may  be  more 
lamps  lighted  even  using  the  same  size  of 
storage  cell.  The  following  tables  afford  op- 
portunity for  determining  the  dimensions  of 
the  cells  and  their  electrical  characteristics: 


STORAGE  BATTERY  FOR  THE  FARM   1 53 


-j 

-j 

u 

U 

HH 

1— 1 

14 

O 

w 

CO 

H-) 

a 

m 

w 

< 

u 

H 

O 

z 

N 

0 

«          5 

8 

CWD 

He*        lofflo 

< 

M 

* 

O 

Q 

w 

to         •*         Ov 

■* 

O 

ON 

On 

M              CO 

U1 

■M. 

O 

q 

*?    5s 

H|«              5 

8 

< 

■4- 

0 

to 

ITi               M 

to             -*             CO 

co 

CJJ 

t-» 

t^ 

W               CO 

•<*• 

wa 

„ 

0 

00 

1 

ui 

««      HS 

H 

•            2 

0 

< 

VO 
co 

0 

VO 

3 

w               VO 

u 

1 

CO 

VI 

«. 

^ 

0 

? 

N 

M 

qs 

He 

< 

Ov 

c» 

10 

Ul 

CO 

U 

■)           CO           O 

10 

■* 

■* 

H 

^ 

^ 

0 

t 

w> 

N 

2ft 

H» 

.           ^             *? 

< 

CO 

00 

0 

O 

M 

N 

t/ 

1             CO              CO 

VO 

CO 

co 

v». 

«, 

0 

I 

IO 

C* 

ccto 

10 

H-h 

Ha 

}        t-|« 

■> 

oa 

6 

VO 

■* 

-*• 

** 

CO 

L/ 

1         CO 

M 

N 

N 

c* 

V). 

J 

■* 

N 

wloo 

Ho 

>        nh 

0 
0 

OS 

t^. 

00 

VO 

M 

VO 

c*. 

w 

>         00 

00 

1 

vo 

N 

Ho 

H« 

>          nh 

0 
0 

oa 

■<*■ 

N 

-* 

00 

00 

w 

)          00 

♦J 

T3 

3      ' 

0 

c 

O     . 

3 
O 

a 

O,    • 

n 

e  >- 

•  — 

S.s 

.2  u 

tic  £ 

je 

■0  3 

c  3 

Si 

K 
t 

n 

•       -5 

B 

-C 

1 

'5 

g            V 

£ 

0  ° 
2 

< 

0 

> 

c 
1 

■t 

X 

£ 

154  FARM    ENGINEERING 

TABLE  III 

A  TYPICAL   LEAD    PLATE-BATTERY 


A 

B 

c 

D 

E 

Weight  in  pounds 

35 

55 

72 

88 

103 

Normal  amp.-hour 
capacity 

20 

40 

60 

80 

100 

Amps,  discharge  at 
5-hour  rate 

3-5 

7 

10. s 

14 

17-5 

Voltage 

2.0 

2.0 

2.0 

2.0 

2.0 

Length 

Glass 
J*r  Rubber 

1\" 

6|" 

1\" 
6f" 

yl" 

6f" 

9" 

8|" 

8" 
61" 

Width 

Glass 
Jar  Rubber 

3i" 

1  1  6 

4f" 

3i" 

6|" 

5\" 
3i" 

9k" 

7tV' 

Height 

Glass 
Jar  Rubber 

17" 

13!" 

17" 

M4 

17" 
13!" 

2oi" 
16" 

i/'i 
I3f" 

Price 

Glass 
JaT  Rubber 

#4-34 
6. 10 

$6.90 
9.  l6 

t>  9-37 

12.22 

$  9-94 
12.40 

$14. 12 
18.35 

Table  III  gives  only  one  make  of  cell  and 
only  one  line  except  cell  D,  which  is  another 
line  altogether,  yet  it  is  made  by  the  same  man- 
ufacturer as  the  others.  This  cell,  although 
approximately  the  same  price  as  cell  C,  has  a 
third  greater  capacity.  This  is  owing  to  the 
fact  that  the  plates  are  larger  and  thus  cost 
less  to  make  per  square  foot  of  their  surface,  and 
the  size  of  the  plate  surface  determines  the 
capacity  of  the  battery.  Whenever  batteries 
are  purchased  it  is  important  to  state  to  the 


STORAGE  BATTERY  FOR  THE  FARM    1 55 

manufacturer  not  only  the  capacity  you  re- 
quire and  the  number  of  cells,  but  also  the 
amount  of  space  you  have  available  for  storage. 
Some  manufacturers  will  furnish  lead-lined 
wooden  tanks  with  properly  arranged  com- 
partments for  the  entire  battery  in  place  of  the 
fragile  glass  or  expensive  rubber  receptacles 
for  the  individual  cells.  In  some  instances 
this  will  save  money  on  the  initial  outlay  as 
well  as  upon  the  repair  costs. 


PART  IV 

DRAINAGE  AND  IRRIGATION 

The  Principles  of  Drainage. 
The  Construction  of  a  Tile  Drain. 
Some  Facts  Concerning  Small  Irrigation  Prac- 
tice. 


CHAPTER  XX 
The  Principles  of  Drainage 

The  immediate  purpose  of  drainage  is  evi- 
dent to  any  one.  It  is  to  remove  the  surplus 
water  from  the  land.  The  reasons  why  this 
improvement  results  in  better  crops  is  not  so 
obvious.  It  is  the  purpose  of  this  chapter  to  ex- 
plain briefly  what  drainage  is,  the  reasons  for 
drainage,  the  desirable  drainage  methods  and 
principles  underlying  them,  and  to  give  some 
practical  information  about  drainage  systems, 
thus  making  clear  why  better  crops  result  from 
carefully  planned  artificial  drainage.  The  next 
chapter  will  explain  in  detail  how  to  tackle  any 
particular  job  of  tile  drainage. 

First,  it  is  necessary  to  call  attention  to  the 
well-known  but  easily  forgotten  fact  that  the 
soil  everywhere  is  permeated  with  moisture. 
All  soil  has  some  water  in  it  even  when  it  appears 
to  be  quite  dry.  This  water  may  be  of  two 
kinds,  either  hydrostatic  (ground  water)  or 
159 


l6o  FARM    ENGINEERING 

capillary  moisture.  The  latter  fills  the  small 
pores  between  the  particles  of  soil  above  the 
ground  water  level.  The  former  fills  all  the 
spaces,  big  or  little,  below  that  level.  The  ground 
water  level  is,  of  course,  a  variable  thing,  con- 
stantly shifting  as  the  seasons  are  wet  or  dry. 
Its  location  at  any  particular  time  may  be  de- 
termined by  digging  a  post  hole  or  well  in  the 
soil.  The  level  at  which  the  water  stands  is  the 
ground  water  level  at  that  point.  In  wet 
weather  the  hole  may  be  pretty  full,  while  in  dry 
weather  the  water  level  may  be  several  feet 
below  the  surface.  For  crops  to  thrive  and 
prosper  the  ground  water  level  must  be  several 
feet  below  the  surface  most  of  the  time,  and 
capillary  attraction,  such  as  exerted  by  any 
porous  body  as  a  lump  of  sugar  or  a  sponge,  is 
depended  upon  to  lift  or  suck  up  from  the 
ground  water  sufficient  moisture  for  the  use  of 
plants. 

In  clayey  soils  the  water  does  not  drain  off 
readily  after  a  storm.  Puddles  and  mudholes 
form  on  the  surface  and  only  dry  up  by  evapo- 
ration. The  ground  water  level  is  then  high, 
being  lowered  gradually  by  the  slight  seepage 
through  the  soil  and  by  evaporation  from  the 


THE    PRINCIPLES   OF  DRAINAGE  l6l 

surface.  Before  it  lowers  sufficiently,  however, 
another  storm  comes  and  raises  the  level  again. 
Thus  the  ground  water  in  such  soils  is  always 
high  except  in  times  of  extreme  drought.  It  is 
such  soils  that  are  benefited  by  drainage. 

Any  soil  where  the  natural  drainage  is  poor 
so  that  the  ground  water  level  is  less  than  about 
three  feet  below  the  surface  at  plowing  time 
will  be  benefited  by  artificial  drainage.  Of 
course  all  soils  must  be  drained  in  order  that 
they  may  be  tillable,  but  in  most  cases  this  is 
done  naturally  by  seepage  through  porous  lay- 
ers to  an  impervious  layer  where  there  is  an 
underflow  of  ground  water  carrying  off  all 
surplus  moisture.  All  soils  which  are  sandy  or 
porous  at  the  surface  may  not  be  well  drained 
naturally,  however.  There  may  be  a  clayey 
subsoil  close  to  the  surface  which  is  nearly  as 
detrimental  to  good  drainage  as  though  it  came 
entirely  up  to  the  surface.  Occasionally  such 
lands  cannot  be  drained  advantageously.  In 
other  cases  the  surface  soil  may  not  be  as  porous 
as  expected,  but  the  subsoil  may  be  very  open 
and  give  perfect  underdrainage.  It  is  not 
possible,  therefore,  to  tell  from  mere  inspection 
of  the  surface  soil  whether  or  not   artificial 


l62  FARM    ENGINEERING 

drainage  is  needed.  In  general,  what  is  known 
as  a  "wet"  soil  needs  drainage  as  does  also  a 
"late"  soil,  while  a  "dry"  soil  or  an  "early" 
soil  is  well  drained  naturally. 

The  reasons  for  drainage  are  many,  but  all  are 
contributory  to  one  great  reason,  and  that  is  to 
raise  a  better  crop.  In  many  cases  crops  have 
been  more  than  doubled  on  land  which  was 
tillable  before,  while  the  reclamation  of  swamp 
land  and  production  thereon  of  a  splendid  crop 
is  extremely  common.  Drainage  opens  up  the 
soil  by  removing  the  surplus  water  and  allowing 
the  air  to  enter.  The  air  currents  circulate  all 
through  these  porous  soil  layers.  This  is  bene- 
ficial in  many  ways.  It  makes  the  soil  more 
friable  and  less  likely  to  cake.  It  assists 
necessary  chemical  actions  in  the  soil.  It  pro- 
motes the  growth  of  bacteria  which  are  necessary 
in  order  that  the  soil  materials  may  be  changed 
into  plant  food.  Air  is  essential  to  rugged  root 
development.  If  the  ground  is  water  soaked 
so  that  the  roots  must  cling  close  to  the  surface 
to  breathe,  then  in  times  of  drought  the  water 
level  goes  so  far  below  them  that  capillary 
attraction  will  not  raise  water  for  their  use.  If, 
on  the  other  hand,  the  upper  soil  contains  free 


THE    PRINCIPLES    OF   DRAINAGE  163 

air,  the  roots  strike  deep  into  the  soil  and  the 
comparatively  slight  change  in  water  level  at 
drought  times  does  not  affect  them.  They  have 
a  larger  area  of  capillary  tubes  to  bring  them 
their  water  supply. 

It  is  a  fact  that  drained  soil  when  work- 
able has  far  more  water  in  it  than  undrained 
soil  when  in  the  same  tillable  condition.  Well- 
drained  soils  are  more  open  and  less  compact 
and  therefore  hold  more  water  in  suspension 
than  undrained  soils.  They  have  greater  cap- 
illary power  because  they  are  more  porous,  so 
that  long  after  crops  in  undrained  soils  have 
perished  those  tiny  capillary  tubes  in  the 
porous  soil  supply  water  to  their  plants.  The 
small  amount  of  water  that  does  fall  in  the  dry 
season  can  be  much  better  conserved  in  drained 
soils  because  it  is  possible  to  get  on  the  land  at 
once  and  cultivate  it. 

Drained  soils  are  from  5  to  10  degrees  warmer 
than  undrained  soils  in  the  spring  months,  and 
somewhat  warmer  most  of  the  time.  It  is 
possible  to  get  on  a  drained  field  from  three 
weeks  to  a  month  earlier  in  the  spring  because 
of  this.  The  water  is  carried  off  and  the  air  gets 
in  the  soil,  warming  it  up.     There  is  not  the 


164  FARM    ENGINEERING 

cooling  effect  of  continued  evaporation.  The 
sun's  heat  warms  the  soil  and  doesn't  have  to 
first  evaporate  the  surplus  water.  Seeds  germi- 
nate better  in  a  warmer  soil,  and  by  getting 
such  an  early  start  the  crops  are  well  along  in 
hot  weather  so  that  they  can  stand  drought 
better,  besides  allowing  the  farmer  finally  to 
take  advantage  of  the  early  markets.  To  a 
great  extent  the  "freezing  out"  and  "heaving" 
of  winter  grain  and  of  posts  will  be  prevented  if 
the  soil  is  drained,  because  the  water  will  be 
drawn  downward  and  not  allowed  to  freeze. 
Drainage  prevents  washing  and  floods  in  wet 
growing  seasons.  It  is,  in  short,  a  stabilizer 
which  makes  uniform  growing  seasons,  allowing 
the  growth  of  a  good  crop  every  year  whether  it 
is  a  wet  season  or  a  dry  one. 

Underdrainage  is  valuable  for  fertilizing  pur- 
poses. It  has  been  mentioned  that  the  passage 
of  air  freely  through  the  soil  helps  the  chemical 
and  bacterial  actions  which  occur.  Fertility 
is  also  added  to  the  soil  with  each  fall  of  rain  or 
snow,  for  as  the  water  is  drawn  through  the 
soil  it  is  deprived  of  the  nitrogen  and  carbonic 
acid  which  it  took  from  the  air  in  passing.  This 
is  all  lost  if  the  water  is  carried  away  by  a  sur- 


THE    PRINCIPLES   OF   DRAINAGE  165 

face  flow.  Manure  and  other  fertilizer  are 
drawn  down  through  the  soil  layers  by  the 
water,  and  surface  washing  is  prevented. 

Surface  drainage  by  ditches  will  not  give  all 
these  benefits  but  it  is  beneficial  in  many  places, 
for  it  lowers  the  ground  water  level  and  permits 
cultivation.  Underdrainage  is,  however,  the 
advisable  method,  and  this  can  be  best  accom- 
plished by  modern  tile  drains.  Both  cement 
and  clay  are  used  for  tiling,  and  there  really  is 
not  much  choice  between  them  if  they  are 
properly  made.  Usually  cement  tile,  if  used, 
is  made  at  home  by  the  farmer  while  clay  tile 
is  purchased.  Under  these  conditions  the  cost 
of  the  cement  tile  is  about  half  that  of  the  clay, 
if  labour  is  not  counted.  The  mixture  used  is 
one  part  cement  to  four  parts  of  clean,  sharp 
sand  for  the  smallest  sizes,  and  one  part  cement 
to  three  parts  of  sand  for  the  larger.  With  a 
hand  machine  two  men  can  construct  1,000 
feet  of  four-inch  tile  in  about  two  days  of  eight 
hours  each  at  a  cost  of  from  #8  to  $10  for  the 
materials  used.  The  cost  of  clay  tiles  is  approx- 
imated in  the  following  table,  including  freight 
rates  for  100  miles.  As  this  tile  is  made  in  every 
section  of  the  United  States,  no  difficulty  should 


i66 


FARM    ENGINEERING 


be  met  with  in  getting  it  at  any  time  and  in  any 
quantity. 


PRICES, 

WEIGHTS,  AND  COST  OF  LAYING  CLAY  TILE 

Tile 
Diameter 

Price  per 

1,000  ft. 

Cost    per    rod 
for  laying  3 
ft.  deep 

Pounds  per  ft. 

Average  car- 
load 

4  in. 
1    « 

$  18 

26 

*0 

33 
33 

6 

8 

6,500  ft. 

5>ooo  " 

6    " 

35 

33 

11 

4,000  " 

7  " 

8  " 

IO     " 

45 
6o 
8o 

35 
40 

45 

14 

18 

25 

3,000  " 
2,400  " 
1,600  " 

12     " 

120 

5o 

33 

1,000  " 

The  grading,  depth,  and  spacing  of  tile  for 
any  particular  job  depends  upon  local  con- 
ditions and  on  the  size  of  tile  used.  Large 
tile,  as  used  in  mains,  may  have  a  fall  as  slight 
as  one  inch  in  ioo  feet,  but  small  tile  used  for 
laterals  or  side  branches  must  have  at  least 
twice  that  amount.  A  greater  fall  is  desirable. 
Lines  of  tiling  across  a  slope  to  prevent  the 
seepage  of  water  down  the  slope  should  have 
considerable  fall;  six  to  ten  inches  in  ioo  feet  is 
little  enough. 

The  depth  of  lines  of  tile  depends  largely  on 
the  spacing  of  the  lines.  The  deeper  they  are 
the  farther  apart  they  may  be  spaced.     The 


THE    PRINCIPLES    OF   DRAINAGE  167 

closer  the  lines  are  laid,  the  shallower  they  may 
be  placed.  Three  feet  is  the  common  depth 
in  clay  and  four  feet  in  a  sandy  soil.     In  the 


,2Z5. 


Fig.  41. — A  natural  system  of  drainage 

former  case  the  laterals  are  placed  four  rods 
apart;  in  the  latter,  eight  rods  apart.     Portions 


i68 


FARM    ENGINEERING 


of  the  field  may  need  closer  lines.  A  simple 
calculation  shows  that  in  the  former  case  forty 
rods  of  tiling  is  needed  per  acre  for  the  laterals, 
while  if,  as  in  the  latter  case,  they  are  eight  rods 
apart,  twenty  rods  of  tiling  is  enough. 

The  cost  of  draining  depends,  of  course,  on 
the  depth  and  spacing.  It  ranges  from  $14  to 
$40  per  acre.  The  average  cost  in  a  great 
number  of  cases  was  $25  per  acre,  using  four- 
inch  tile  for  laterals  and  six  to  ten  inch  for 
mains.  The  following  table  shows  the  approx- 
imate cost  per  acre  under  various  conditions, 
using  a  four-inch  tile  at  $18  per  thousand  and 
estimating  cost  of  laying  as  given  in  the  previ- 
ous table.  This  table  following  makes  allowance 
for  digging  ditch,  purchasing  tile,  laying  tile,  and 
refilling  ditch.     Cartage  will  have  to  be  added : 

APPROXIMATE    COST   OF  TILING   PER  ACRE 


Spacing 

Feet  required  per  acre 

Cost  per  acre 

200  ft.  apart 

218    ft. 

#IO 

150 "        " 

29O     " 

13 

120  "        " 

363      " 

16 

100  "        " 

436     " 

18 

80  "        " 

545    " 

24 

60  "        " 

726   " 

32 

So  -       - 

872   " 

38 

40 

1,090   " 

48 

30 

M50   " 

64 

THE    PRINCIPLES    OF   DRAINAGE  169 

The  systems  of  tiling  used  are  five  in  number, 
the  natural  system,  the  gridiron,  the  herring- 
bone, the  single  line,  and  the  cross-the-slope 
system,  all  of  which  are  shown  in  the  accom- 
panying diagrams.  In  the  natural  system  single 
lines  of  tile  are  placed  along  the  lowest  part  of 
the  various  wet  marshes,  no  attempt  being 
made  to  lay  out  a  systematic  design.  It  is,  in 
many  ways,  the  most  economical  plan  and 
frequently  the  most  efficient.  The  gridiron 
system  is  used  in  flat  fields  requiring  thorough 
covering.  It  is  very  economical.  The  herring- 
bone is  rather  a  cross  between  the  former  two. 
It  is  used  in  broad  fields  with  a  natural  de- 
pression running  through  it,  along  which  the 
main  is  placed.  It  is  not  so  economical  as  the 
gridiron  plan  but  is  necessary  in  some  places. 
The  single  line  is  used  for  inexpensive  first- 
cost  systems.  Its  upkeep  may  be  somewhat 
greater  than  the  others  because  each  line  has 
an  outlet  which  must  be  kept  free  and  clean. 
The  cross-the-slope  arrangement  is  used  to  in- 
tercept water  flowing  down  the  hill  in  rather 
moist  hillside  areas  having  considerable  slope. 
The  choice  of  the  system  to  be  used  depends 
on  the  individual.     In  most  cases  the  gridiron 


170 


FARM    ENGINEERING 


arrangement  is  desirable.  In  every  case  the 
main  should  run  along  the  lowest  ground  and 
the  laterals  run  parallel  with  each  other  and 


Fig.  42. — Other  drainage  systems.    A — Gridiron.    B — Single  line. 
C — Herringbone.     D — Cross-the-slope 


THE    PRINCIPLES    OF   DRAINAGE  171 

with  the  slope,  unless  the  latter  is  very  steep. 
It  is  thus  seen  that  the  field  will,  to  some  extent, 
lay  itself  out  and  choose  its  own  system. 

Frequently  catch  basins  are  desirable  along 
the  line  of  drains  to  carry  away  some  particular 
flow  of  surface  water.  They  are  easily  placed 
at  the  time  the  drains  are  laid.  In  every  case 
care  should  be  taken  to  prevent  dirt  and  silt 
entering  the  drain  at  these  places.  Such  tile  lines 
should  be  six  inches  in  diameter  at  least.  The 
basins  are  merely  pits  filled  with  broken  stone. 
Occasionally  they  are  walled-up  cisterns  built  of 
concrete  covered  with  a  protective  grating. 

The  profits  of  draining  depend  largely  upon 
the  skill  shown  in  planning  and  executing  the 
work.  Not  always  will  the  first  crop  pay  for 
the  drainage  installation,  but  in  every  case  where 
intelligent  management  is  used  four  crops 
should  show  such  an  increase  as  to  more  than 
pay  for  the  system  and  interest  on  the  invest- 
ment during  that  period  of  time.  In  hundreds 
of  cases  one  crop  on  land  which  had  never 
before  felt  the  plow  has  paid  many  times  over 
for  the  drainage  operations.  In  a  few  cases 
drainage  has  not  increased  the  crop  any  but  has 
made  it  earlier  and  so  of  more  value. 


CHAPTER  XXI 

The  Construction  of  a  Tile  Drain 

There  are  at  least  four  distinct  steps  in  the 
construction  of  any  drain:  (i)  locating  the  out- 
lets and  laying  out  the  tile  lines;  (2)  digging  the 
ditch;  (3)  making  the  outlet  bulkheads  and  lay- 
ing the  tile;  (4)  filling  the  ditch.  The  first  step 
includes  making  a  sketch,  however  rough  it  may 
be,  of  the  land  to  be  drained.  Note  on  it  the 
slope  of  the  land  and  the  points  of  the  compass. 
Mark  the  line  of  lowest  land.  Make  this 
sketch  complete  for  a  whole  drainage  system, 
no  matter  how  little  is  to  be  done  at  the  present 
moment.  Then  the  little  that  is  done  may 
be  made  to  accord  with  the  plan  for  the 
whole,  and  trouble  later  on  may  be  avoided. 
Then  with  this  sketch  in  hand  go  over  the  land 
carefully  and  follow  the  general  order  given 
below.  This  is  suggestive  and  not  exacting,  but 
it  has  been  found  from  much  experience  to  give 
the  most  desirable  results. 

172 


CONSTRUCTION   OF   A   TILE   DRAIN  1 73 

1.  Locate  the  outlets  of  the  mains  at  the 
lowest  points  of  the  land  emptying  into  a 
present  waterway  or  into  an  open  ditch  leading 
to  some  waterway.  Have  as  few  outlets  as 
possible,  for  they  are  always  troublesome  and 
must  be  carefully  watched  to  prevent  clogging. 
Usually  one  is  enough.  It  will  pay  in  most 
cases  to  build  a  concrete  casing  for  the  outlet, 
and  across  the  opening  embed  bars  of  iron  to 
prevent  the  entrance  of  anything. 

2.  Locate  the  main  or  mains  along  the  line 
of  lowest  ground.  This  can  be  determined  by 
following  the  channel  along  which  the  surface 
water  flows  in  flood  times.  If  the  field  is  nearly 
flat,  locate  the  main  along  one  side,  as  by  so  doing 
you  can  save  tiling  and  save  joints. 

3.  Mark  line  of  main  and  lines  for  laterals 
by  driving  stakes  firmly  into  the  ground  every 
fifty  feet.  Make  the  laterals  parallel  to  each 
other  and,  so  far  as  possible,  have  all  lines 
straight.  If  curves  are  necessary  make  them 
with  a  long  radius.     Avoid  sharp  bends. 

4.  Determine  total  fall  of  each  main  and 
lateral  by  using  a  sight  level.  Divide  by  the 
number  of  stakes  and  thus  get  fall  between  each 
two  consecutive  stakes. 


174  FARM    ENGINEERING 

5.  Calculate  depth  of  ditch  below  top  of 
each  stake  to  give  proper  fall.  Make  depth 
gauge  of  a  pole  and  a  cross-piece  at  this  calcu- 
lated depth  away  from  the  end  of  the  pole. 

6.  Stretch  a  cord  from  top  of  one  stake  to 
the  next  as  a  guide  in  digging.  This  line  should 
have  the  proper  calculated  fall  which  the  ditch 
is  to  have,  so  that  if  the  depth  gauge  is  placed 
anywhere  with  the  cross-piece  on  the  line  the 
end  of  the  pole  will  be  on  the  bottom  of  the 
ditch. 

7.  Begin  digging  at  the  outlet  or,  if  outlet 
is  to  empty  into  an  open  ditch  which  runs  to 
some  waterway,  dig  this  ditch  first.  Then 
begin  the  tile  drain  main  ditch  at  outlet,  making 
ditch  a  foot  to  one  side  of  line  of  stakes  so  that 
position  of  stakes  will  be  preserved.  Start 
ditch  with  plow  and  then  use  hand  tools.  Dig 
ditch  just  wide  enough  to  stand  in,  perhaps 
fourteen  inches  wide  at  top  and  eight  inches  at 
bottom  for  a  ditch  three  feet  deep. 

8.  After  getting  ditch  the  right  depth  at 
each  stake,  sight  along  the  bottom  to  remove  all 
humps  and  hollows  and  make  a  smooth,  gradual, 
and  continual  slope.  Test  this  grade  in  many 
places  by  measuring  down  from  line  with  the 


CONSTRUCTION   OF   A   TILE    DRAIN  I75 

depth  gauge.     This  part  of  the  work  is  very  im- 
portant and  needs  care. 

9.  Groove  the  bottom  of  the  ditch  carefully 
and  lay  the  tile  in  the  grooves.  These  grooves 
are  of  great  value  in  laying  round  tile.  The 
tile  should  be  laid  as  fast  as  the  ditch  is  dug  and 
put  in  shape.     Start  laying  the  tile  at  the  outlet. 

10.  Begin  at  outlet  and  lay  main.  The 
first  few  feet  should  be  of  glazed  or  hard-burned 
tile  to  resist  frost.  The  first  few  joints  should 
be  cemented. 

11.  Wall  up  outlet  with  stone  to  protect  it, 
or  build  the  concrete  bulkheads.  This  is  im- 
portant and  should  not  be  slighted.  It  may  be 
postponed  until  later,  if  desired,  but  must  not 
be  forgotten. 

12.  Lay  main  as  far  as  first  lateral  and  put 
in  a  Y-connection  and  lay  the  first  few  feet  of 
that  lateral.  Keep  on  laying  main  and  the 
adjacent  ends  of  the  laterals  until  main  is  com- 
plete. 

13.  Go  back  and  finish  laying  laterals. 

14.  Place  a  flat  stone  against  the  upper  end 
of  each  tile  line  so  as  to  close  it  against  the 
entrance  of  dirt  or  rubbish. 

15.  Cover  every  hole  or  crack  in  or  between 


I76  FARM    ENGINEERING 

tile  larger  than  one  quarter  inch  by  a  piece  of 
broken  tiling. 

16.  Cover  tile  with  loose  earth  carefully. 
Then  fill  ditch  in  most  convenient  and  rapid 
way.  A  scraper  made  of  a  plank  on  edge  some- 
thing like  a  snow-plow  will  do  good  work  if 
pulled  along  the  ground  at  one  side  of  the 
ditch.  So  will  a  road  scraper  or  a  split-log  drag. 
By  turning  several  furrows  into  the  ditch  with 
an  ordinary  horse-plow,  the  filling  will  be  very 
rapidly  done. 

The  following  suggestions  may  be  of  value  in 
connection  with  the  work: 

1.  Plan  the  work  and  start  deep  enough  to 
drain  the  whole  field. 

2.  If  the  natural  slope  is  not  good  enough 
the  ditch  may  be  made  a  little  shallow  at  the 
upper  end,  grading  to  the  proper  depth  gradu- 
ally. Remember  that  the  grade  should  be 
uniform  along  any  length  of  tile. 

3.  Get  all  the  fall  possible. 

4  Make  joints  real  tight.  Water  can  get  in 
where  sand  and  dirt  cannot.  No  opening 
should  be  more  than  one  fourth  of  an  inch. 

5.     In   quicksand   cover  each  joint  with   a 


CONSTRUCTION   OF   A  TILE   DRAIN  I77 

piece  of  roofing  paper.  A  little  concrete  laid  in 
the  bottom  of  the  ditch  and  grooved  will  help 
greatly  in  maintaining  the  grade  through  a  run 
of  quicksand. 

6.  Keep  an  accurate  map  of  the  whole  field, 
marking  carefully  the  location  of  joints  and 
dead  ends. 

7.  Cover  end  of  last  tile  laid  if  work  is 
interrupted  so  as  to  prevent  filling  if  a  heavy 
rain  comes  on  before  work  is  resumed. 

8.  The  first  dozen  joints  next  to  outlet  should 
be  cemented  tight  to  insure  perfect  results. 
The  greatest  care  must  be  taken  of  outlets. 

9.  Use  no  tile  smaller  than  four  inches  in 
diameter.  It  doesn't  pay.  They  fill  up  quickly 
and  their  first  cost  is  but  slightly  less  than  the 
four-inch.  Remember  the  four-inch  has  nearly 
twice  the  carrying  capacity  of  the  three-inch,  and 
variations  in  grade  which  would  be  disastrous 
to  the  three-inch  will  not  greatly  affect  the 
larger  sizes. 

10.  Every  tile  should  be  perfectly  round  and 
should  give  a  clear,  metallic  ring  when  struck. 

11.  Open  ditches  should  be  seven  feet  deep 
and  at  least  three  feet  wide  with  45  degree 
sloping  sides. 


CHAPTER  XXII 

Some    Facts   Concerning   Small 
Irrigation    Practice 

It  is  now  recognized  that  practically  all  crops 
may  be  benefited  by  proper  irrigation  where 
water  is  cheap  and  plentiful.  It  is  not  as  uni- 
versally known  that  proper  drainage  is  essential 
to  make  the  benefits  from  irrigation  as  great  as 
possible.  The  danger  without  drainage  is  that 
the  raising  of  the  ground  water  with  consequent 
capillary  rise  and  evaporation  will  cause  too 
great  an  accumulation  of  undesirable  soil  salts 
in  the  surface  layers  of  the  earth.  This  is  a 
subject  that  has  attracted  the  attention  of 
many  experts  and  what  is  referred  to  when  the 
statement  is  made  that  continued  irrigation  is 
the  cause  of  soil  deterioration.  Proper  culti- 
vation of  irrigated  lands  and  care  in  the  use  of 
water  will  do  much  to  offset  the  disadvantage  of 
poor  drainage.  Cultivation  of  the  soil  after 
applying  the  water  will  prevent  rapid  evapo- 

178 


SMALL    IRRIGATION    PRACTICE  1 79 

ration  and  will  allow  the  crops  the  full  use  of  the 
water  applied,  thus  making  for  economy  in  water. 

The  desirability  of  cultivation  leads  to  the 
belief  that  the  method  known  as  subirrigation 
is  the  best  one  to  follow.  It  has  received  much 
thought  and  study,  but  the  results  from  it  are 
entirely  unsatisfactory  because  of  the  initial 
outlay  involved  and  the  fact  that  for  many 
crops  the  inequalities  of  distribution  are  fatal. 
The  furrow  system  is,  on  the  other  hand,  the 
cheapest,  simplest,  and  probably  the  most 
widely  used  method.  Lately,  too,  a  method  of 
sprinkling  has  been  used  with  success  on  small 
fields,  known  in  some  sections  as  the  "Skinner 
Irrigation  System." 

Particularly  in  sloping  fields  is  the  furrow 
system  easily  laid  out.  The  furrows  are  run 
down  the  slope,  either  directly  or  diagonally, 
on  an  angle  depending  upon  the  amount  of 
grade.  Sometimes  they  are  laid  out  in  wide, 
sweeping  curves.  The  steeper  the  grade  the 
nearer  to  the  horizontal  must  the  furrows  be  cut, 
the  grade  being  thus  lessened.  Such  furrows  are 
connected  to  the  main  furrow  by  curved  flumes. 
The  main  feeding  furrow  runs  along  the  top  of 
the  grade  at  the  upper  ends  of  the  laterals. 


l8o  FARM    ENGINEERING 

More  than  one  main  or  flume  will  be  needed  in 
most  cases,  these  being  spaced  apart  down  the 
grade  an  amount  depending  upon  the  distance 
a  stream  will  run  in  the  branch  furrows.  No 
rule  can  be  given  for  this,  as  it  depends  entirely 
upon  how  much  water  is  flowing,  that  is,  upon 
the  size  of  the  stream  in  the  furrow,  and  also 
upon  the  character  of  the  soil.  In  porous  soils 
furrows  from  40  feet  to  200  feet  will  be  as 
long  as  desirable,  while  in  closer  packed  land 
furrows  may  run  as  long  as  600  feet.  Usu- 
ally they  are  from  one  foot  to  four  feet  apart 
and  are  from  three  to  twelve  inches  deep.  The 
deeper  they  are  made  the  less  evaporation  from 
them  per  unit  in  the  same  length  of  time. 

Although  particularly  adapted  for  use  with 
crops  planted  in  rows,  the  furrow  system  is  of 
great  value  in  all  types  of  planting.  It  is  very 
adaptable  and  may  be  widely  modified.  By 
damming  the  furrows  at  any  time  the  fields 
may  be  readily  flooded,  if  desired,  and  the 
advantages  of  the  flooding  system  obtained. 
This  is  very  desirable  with  extremely  porous 
tracts  where  the  water  must  be  gotten  over  the 
ground  quickly.  The  advantages  of  the  furrow 
system  are  that  the  entire  surface  of  the  ground 


SMALL    IRRIGATION    PRACTICE  l8l 

is  not  wet  and  therefore  is  not  in  a  condition  to 
bake;  there  is  less  evaporation  than  would  be 
with  a  thin  sheet  spread  out  over  the  field;  the 
water  is  near  the  roots  and  a  deeper  root  growth 
is  promoted. 

The  main  ditches  for  irrigation  projects 
should,  if  possible,  be  laid  along  boundary  lines 
or  fences  in  order  that  they  may  not  interfere 
with  other  operations.  Often  it  is  desirable  to 
convey  the  water  from  its  source  to  the  furrows 
by  means  of  concrete  or  clay  pipes  rather  than 
with  open  ditches.  It  cuts  up  the  land  less  to 
do  this  and  is  less  likely  to  hinder  farm  work  in 
general. 

To  insure  equal  distribution  of  water  in 
furrows,  boards  may  be  placed  in  the  banks  of 
the  main  ditches  and  adjusted  so  that  the 
proper  amount  of  water  flows  over  the  edge. 
The  time  taken  for  the  water  to  run  through 
the  furrows  may  be  between  fifteen  minutes  and 
two  hours,  depending  upon  a  multitude  of  con- 
ditions. The  flow  per  furrow  ranges  from 
fifteen  to  thirty  gallons  per  minute.  The  irri- 
gation flow  usually  continues  for  perhaps  two 
or  three  days  with  an  interval  between  appli- 
cations of  from  seven  to  twenty  days. 


1 82  FARM    ENGINEERING 

The  Skinner  system  requires  an  elevated 
tank  or  a  pump  connected  to  a  water  course 
and  able  to  keep  up  a  continuous  supply  for  the 
required  length  of  time.  The  main  sprinkler 
pipes  are  usually  not  over  250  feet  long  but 
there  may  be  a  number  of  them.  Every  three 
or  four  feet  there  are  outlets  or  faucets.  The 
pipes  for  lengths  such  as  this  are  two  inches  in 
diameter  and  the  outlets  are  three  fourths  of  an 
inch.  A  supply  which  will  provide  about  fifty 
pounds  pressure  is  satisfactory  for  a  system  of 
this  kind,  and  there  are  several  working  well 
under  somewhat  less  pressure.  A  water  supply 
of  1,000  barrels  will  supply  an  acre  and  a  half 
with  sufficient  moisture  for  about  four  days 
during  the  dry  season.  Obviously  this  system 
is  of  greatest  value  in  small  plots,  and  the 
operation  of  the  various  sections  of  pipe  may  be 
regulated  to  suit  the  needs  of  that  particular 
place. 

In  every  case  it  must  be  remembered  that 
irrigation  which  provides  continuous  moisture 
is  better  than  one  soaking  and  then  a  dry  spell 
followed  by  another  soaking.  Too  slight  an 
amount  of  water  should  not  be  applied,  but, 
unless  the  soil  is  porous  and  able  to  retain  large 


SMALL   IRRIGATION    PRACTICE  1 83 

quantities  of  capillary  moisture,  a  real  heavy 
application  should  be  avoided  as  should  also  an 
extended  period  between  applications.  A  medium 
amount  applied  quite  frequently  is  desirable 
to  promote  the  continual  and  rugged  growth 
of  the  plants.  The  water  should  be  applied 
each  time  before  the  plant  shows  signs  of 
distress  in  order  that  there  may  be  no  hesi- 
tation in  growth  and  no  tendency  to  put  out  un- 
desired  new  shoots  when  growth  is  again  fostered 
by  moisture  applied  after  a  dry  period.  The 
plant  and  the  soil  should  be  watched  together, 
frequent  and  careful  investigations  being  made 
of  their  condition. 

The  cost  per  acre  to  put  any  field  in  con- 
dition for  irrigation  varies  widely  with  the 
system  used  and  with  the  local  conditions.  It 
ranges  between  #5  and  $20.  The  cost  of  apply- 
ing the  water  afterward  is  also  variable,  as 
might  be  expected.  It  is  usually  figured  either 
as  the  cost  of  applying  an  amount  of  water 
equivalent  to  a  foot  deep  over  an  acre  (called  an 
acre-foot)  or  as  the  cost  of  irrigating  an  acre  for 
a  season  or  a  year.  The  following  tables  give 
the  amount  of  water  required  to  cover  an  acre 
to  any  certain  depth: 


184  FARM    ENGINEERING 

FLOW   OF   WATER   REQUIRED   TO    COVER   AN   ACRE 


Equivalent  depth  of 
water  over  the  acre 


inch 


Gallons  required  to 
cover  the  acre 


27,157  gallons 

54>3*4 

81,470 

108,627 

135.784 
271,567 
325,880 


Gallons  per  minute  re- 
quired to  furnish  this 
amount  in  24  hours 


18.9  gals,  per  min 

377  " 

56.6  " 

75-4  " 

94-3  " 

188.6  " 

226.3  " 


The  next  table  gives  the  same  information 
but  in  a  little  different  form,  being  arranged  to 
show  the  amount  of  surface  any  particular  flow 
will  cover  to  the  depth  of  one  inch. 


ACRES    COVERED    BY   ANY    FLOW    PER   MINUTE 


Gallons  per  minute  flow- 
ing for  24  hours 

Total  gallons  used  per 
24  hours 

Number  of  acres  covered 
by  this  to  depth  of  1 
inch 

10 

14,400 

■53 

SO 

72,000 

2 

65 

IOO 

144,000 

5 

3 

200 

288,000 

10 

6 

300 

432,000 

15 

9 

4OO 

576,000 

21 

• 

500 

720,000 

26 

5 

In  most  cases  and  for  most  crops  a  flow  of 
five  to  six  gallons  per  minute  per  acre  is  the 
required  rate.     For  wetting  the  land  to  a  depth 


SMALL    IRRIGATION    PRACTICE  1 85 

of  four  feet,  from  about  2.5  to  6  inches  of 
water  over  the  land  is  required,  depending  upon 
its  degree  of  moisture  when  irrigation  starts. 
Many  investigations  have  given  the  average 
figure  for  complete  irrigation  at  from  4  to  6 
acre-inches  of  water  per  month,  equivalent  to  a 
continual  flow  of  about  2.5  to  3.8  gallons  per 
minute  per  acre  during  the  month.  Of  course 
such  a  continuance  of  flow  is  never  followed,  but 
a  larger  amount  is  used  for  a  shorter  length  of 
time. 

The  cost  of  application  depends  upon  the 
system  used,  the  amount  and  cost  of  water  con- 
sumed, the  frequency  of  application  and  labour 
costs  in  the  locality.  In  the  East  the  cost  of 
applying  a  total  depth  of  four  to  eight  inches  of 
water  per  acre  per  year,  using  the  furrow 
system,  and  with  wages  approximating  $1.50 
per  day,  will  range  from  $25  to  $75  per  acre. 
The  sprinkler  system  under  the  same  conditions 
will  result  in  a  somewhat  larger  cost  usually, 
but  in  no  case  is  it  likely  to  exceed  #100  per  acre 
per  year.  If  the  water  is  city  water  and  pur- 
chased, the  cost  of  it  alone  will  probably  amount 
to  #50  per  acre-foot,  while  pumped  water  will 
cost  but  $12  or  #15  per  acre-foot.     In  the  South 


1 86  FARM    ENGINEERING 

and  West  somewhat  smaller  costs  of  water  pre- 
vail, the  cost  of  pumping  being  considerably 
less  than  that  stated,  and  purchased  water  being 
obtained  in  many  places  for  from  $15  to  $20  per 
acre-foot.  The  cost  of  applying  the  water  per 
acre-inch  per  irrigation  will  run  from  50  cents 
to  $1. 


PARTV 

MISCELLANEOUS   ENGINEERING 
TALKS 

The  Cost  of  Road  Building. 

The  Working  Principles  of  Orchard  Heaters. 

The  Forms  of  Electricity. 


CHAPTER  XXIII 

The   Cost   of   Road   Building 

Conditions  vary  so  much  in  various  states, 
and  even  in  different  counties  of  the  same  state, 
that  it  is  impossible  to  give  an  adequate  treat- 
ment of  this  question  without  going  into  the 
whole  problem  thoroughly.  The  cost  of  build- 
ing the  road  depends  upon  many  factors  such  as 
the  cost  of  labour,  availability  of  materials,  the 
kind  of  road,  the  width,  the  depth  of  surfacing, 
the  cost  of  bridges  and  culverts,  the  traffic  ex- 
pected, and  the  climate,  particularly  as  regards 
rainfall  and  freezing.  There  are  five  distinct 
kinds  of  road  construction  used  in  this  country 
for  pikes — earth  roads;  sand-clay,  gravel,  mac- 
adam and  bituminous  macadam.  In  Texas 
there  is  also  considerably  more  than  a  hundred 
miles  of  shell  roads,  and  there  are  similar  lengths 
in  other  coast  states.  The  following  table  gives 
some  idea  of  the  wide  variation  in  the  cost  of 
roads  in  different  sections. 
189 


I90  FARM    ENGINEERING 

TABLE    OF    COST    OF    ROAD    CONSTRUCTION 


Cost  of  Ro 

ids  per  mile 

In  Texas 

In  U.  S. 

Earth  roads 

From    £60    to   $400. 
Average  in  5  coun- 
ties, $168. 

Sand-clay  roads 

From  $60  to  £2,000. 

From  £387  to  $1,775- 

Average  in  41  coun- 

Average in  17  states 

ties  is  $593. 

is  £723. 

Gravel  roads 

From  $100  to  $4,000. 

From  £940  to  £5,950. 

Average  in  27  coun- 

Average in  31  states 

ties  is  £1,708. 

is  £2,047. 

Macadam  roads 

From  £1,000  to£3,5oo. 

From  £2,153  to£9,i64. 

Average  in  5  coun- 

Average in  34  states 

ties  is  £2,160. 

is  £4,989. 

Bituminous 

In   El   Paso   County 

From       £6,000       to 

macadam 

the  cost  is  £6,000. 

£19,681.  Average  in 
10  states  is  £10,348. 

Shell  roads 

Average  in  3  counties 
is  £3,083. 

In  Texas  the  total  mileage  of  all  public  roads 
is  about  128,971,  of  which  only  2  per  cent, 
are  improved.  Of  the  2,768  miles  of  improved 
roads  by  far  the  greatest  mileage  (about  2,254 
miles)  is  of  sand-clay  construction. 

The  variation  in  the  cost  of  road  building  in 
any  given  way  depends  on  the  width  and  depth 
of  material  among  other  things.  For  sand-clay 
roads  the  average  width  in  seventeen  States  is 
seventeen  feet  and  the  average  depth  of  surfac- 
ing is  nine  inches.  The  gravel  roads  in  thirty- 
one    States    averaged    thirteen   feet   wide   and 


THE    COST   OF   ROAD    BUILDING  191 

seven  inches  deep.  The  average  width  of  a 
macadam  surface  is  thirteen  feet  in  thirty-four 
States  and  the  depth  is  six  inches.  The  average 
width  of  bituminous  macadam  in  ten  States  is 
fifteen  feet  and  the  depth  six  inches. 

Without  doubt  the  sand-clay  road  obtained 
by  using  six  to  eight  inches  of  clay  plowed  and 
harrowed  into  a  sandy  gravel  to  form  a  thorough 
mixture  gives  a  comparatively  low-priced  and 
satisfactory  road,  and  it  is  rapidly  growing  into 
great  favour. 

The  kind  of  road  and  method  of  maintenance 
determines  the  cost  to  a  great  extent.  The 
European  countries  long  ago  saw  the  absurdity 
of  building  good  roads  and  neglecting  them. 
They  therefore  established  a  patrol  system. 
Only  in  New  York  State,  however,  have  we  had 
such  a  system  until  recently,  and  there  it  has 
been  very  successful.  One  patrolman  can  care 
for  six  to  twelve  miles  of  road,  patrolling  the 
entire  section  at  least  twice  a  week,  filling  in 
ruts  and  holes,  repairing  defective  spots  in  the 
surface,  sweeping  the  water-bound  surface,  and, 
in  general,  keeping  the  road  in  first-class  con- 
dition, and  the  ditches,  culverts,  etc.,  clear  so 
that  the  road  may  be  well  drained.     It  is  the 


igi  FARM    ENGINEERING 

practice  of  the  old  adage,  "A  stitch  in  time  saves 
nine."  By  such  a  careful  system  the  cost  of 
maintenance,  based  on  the  pay  of  patrolmen  at 
$2  per  day  for  five  months  in  the  year,  is  about 
$75  per  mile  per  year.  The  present  form  of 
maintenance  of  roads  in  New  Hampshire  and 
elsewhere  is  by  use  of  oil  treatment  covered 
with  sand.     That  costs  $440  per  mile. 

There  can  be  no  question  but  what  the  auto- 
mobile is  the  cause  of  great  deterioration  of 
roads.  The  surface  is  loosened  by  the  tan- 
gential push  of  the  tire  as  it  grips  the  road. 
Then  there  is  much  slip  of  the  tire  on  the  road  and 
the  rubber  picks  up  much  of  the  small  stuff.  In 
a  test  under  unusually  heavy  traffic  of  unusually 
heavy  motor  vehicles,  a  stretch  of  gravel  road 
cost  over  #2,000  per  mile  for  five  months'  main- 
tenance as  against  a  negligible  sum  before  the 
circumstances  which  caused  the  heavy  motor 
traffic. 

For  roads  requiring  merely  occasional  scrap- 
ing and  dragging  to  keep  them  in  good  repair, 
£5  per  year  per  mile  is  an  average  figure. 

As  to  the  distribution  of  cost,  in  New  York 
and  a  number  of  other  States  the  trunk  lines 
are  built  at  the  cost  of  the  State,  while  other 


THE    COST   OF   ROAD    BUILDING  I93 

roads  are  built  at  joint  expense.  Usually  the 
State  takes  charge  of  the  work  and  pays  50  per 
cent,  of  the  cost,  the  county  paying  35  per  cent, 
and  the  town  15  per  cent.  The  maintenance  is 
also  divided  up. 


CHAPTER   XXIV 

The  Working  Principles  of  Orchard 
Heaters 

Many  of  the  Eastern  farmers  have  found  out 
that  orchard  heaters  are  not  as  satisfactory  in 
one  orchard  as  in  another,  and  wish  to  know 
the  principles  of  operation  in  order  that  they 
may  be  used  with  the  greatest  efficiency.  Others 
have  tried  them  but  once  and  without  success. 
Full  stories  of  experiences  are  hard  to  get  with- 
out being  coloured  somewhat  by  the  prejudice 
of  the  writer.  This  plan  of  orchard  heating  in 
times  of  unseasonable  frosts  has  been  tried  out 
for  years  in  the  Western  States  with  great 
success.  Fruit  growers  in  New  York,  New 
Jersey,  Connecticut,  and  Massachusetts  have 
taken  it  up  more  or  less  in  the  last  few  years. 
In  Canada  very  few  orchards  are  so  protected. 
The  basic  idea  is  to  start  a  multitude  of  small 
fires  in  various  parts  of  the  orchard  when  the 
temperature  goes  so  low  as  to  give  a  possibility 

194 


PRINCIPLES    OF    ORCHARD   HEATERS         I95 

of  injuring  the  crop,  particularly  about  blossom 
or  bud  time.  The  usual  fire  is  a  can  of  burning 
oil  which  gives  off  a  dense  smoke.  Sometimes 
soft  coal  is  burned,  but  it  is  less  satisfactory 
because  of  the  time  required  in  starting  it  and 
the  fact  that  it  cannot  be  readily  quenched 
without  dumping  and  wasting  considerable  fuel. 
The  oil  heaters,  on  the  other  hand,  smoke  up 
well  and  burn  from  the  beginning,  and,  if  there 
is  a  cover  on  the  container  in  which  the  oil 
is  held,  these  heaters  may  be  put  out  by  simply 
closing  the  cover  and  shutting  off  the  supply  of 
air.  As  many  as  three  or  four  thousand  of 
these  small  cans  are  used  in  some  of  the  orchards. 
The  protection  afforded  comes  largely  from  the 
great  cloud  of  smoke  which  hangs  low  over  the 
orchard,  holding  in  the  heat  from  the  fires.  If 
a  strong  wind  gets  at  this  cloud  and  dissipates 
it  readily,  the  heaters  will  not  be  satisfactory. 
If  the  orchard  is  located  high  and  unprotected 
in  order  to  get  good  air  drainage,  the  chances  are 
that  this  form  of  heating  will  be  very  difficult 
to  arrange.  The  best  location  is  one  that  is 
somewhat  sheltered,  as  where  there  has  been  a 
windbreak  erected  or  where  there  is  a  natural 
windbreak.     Particularly  in  valleys  surrounded 


I96  FARM    ENGINEERING 

by  small  hills  this  method  of  frost  fighting  is 
very  successful.  In  such  places  as  these  the 
cold  winds  are  prevented  by  the  smoke  clouds 


0OU  ras  Mtmu  lim* 


Fig.  43. — An  orchard  heater 


from  driving  in  and   making  cold   air  pockets 
around  the  trees.     Many  farmers  in  setting  out 


PRINCIPLES    OF   ORCHARD   HEATERS         I97 

new  orchards  arrange  windbreaks  against  the 
winds  found  to  be  most  damaging,  with  the  idea 
of  utilizing  the  orchard  heaters  when  the  trees 
come  into  bearing. 

The  particular  type  of  burner  is,  of  course, 
immaterial  so  far  as  effectiveness  goes.  It  is 
merely  a  case  of  convenience.  Small  fires  of 
damp  brushwood  or  sawdust,  perhaps  with  a 
little  soft  coal  thrown  on,  have  been  used  suc- 
cessfully in  the  early  days  of  experimentation 
and  are  still  retained  by  some  fruit  growers. 
One  man  built  his  fire  on  a  portable  arrangement 
and  dragged  it  slowly  in  and  out  through  the 
orchard  with  really  remarkably  good  results,  but, 
of  course,  at  the  expense  of  considerable  labour 
and  inconvenience.  The  difficulty  of  starting 
such  a  number  of  heaters  in  a  short  time  has  been 
solved  by  a  simple  electrical  device  that  any 
farmer  can  make.  The  oil  container,  built  in 
something  the  shape  of  a  milk  pail,  has  a  hinged 
cover  with  a  weight  attached  to  it  tending  to  hold 
the  cover  open  at  all  times.  A  piece  of  fusible 
metal  is  tied  so  as  to  hold  the  cover  down.  In  a 
little  pocket  alongside  of  this  fusible  link  there  is  a 
small  amount  of  gunpowder  and  a  wick  leading 
from  the  oil  can,  as  shown  in  Fig.  43.    There  is  an 


I98  FARM    ENGINEERING 

ordinary  gasoline  engine  spark  plug  arranged 
close  to  the  powder.  If  the  plug  is  too  expen- 
sive, just  the  bared  ends  of  two  wires  held 
securely  a  very  tiny  distance  apart  will  do. 
These  spark  gaps  are  connected  in  circuit  with 
a  spark  coil,  so  that  by  closing  a  switch  from 
the  battery  to  the  coil  a  spark  will  be  caused  to 
jump  the  gaps.  In  doing  this  the  powder  is  ig- 
nited and  lights  the  wick.  The  burning  wick 
melts  the  fuse,  releasing  the  cover  and  allowing 
the  weights  to  pull  the  cover  open.  The  wick 
thereupon  ignites  the  oil  within  the  can.  By 
setting  a  stop,  the  cover  may  be  opened  a  small 
or  a  large  amount,  thus  regulating  the  fire  to 
suit  the  conditions. 


CHAPTER  XXV 

The   Forms  of  Electricity 

Electricity  is  the  same  substance  no  matter 
whether  it  is  generated  by  chemical  action,  by 
friction,  or  by  any  other  one  of  the  many  ways 
in  which  it  is  possible  to  generate  it.  Just  in 
the  same  way  water  is  the  same  substance 
whether  it  is  in  the  form  of  ice,  of  water,  or  of 
steam.  Yet,  although  water  consists  of  a  com- 
bination of  oxygen  and  hydrogen,  and  it  is  the 
same  combination  in  whatever  form  the  water 
is,  we  know  that  steam  will  act  on  a  thing 
differently  from  what  ice  will.  That  is  because 
steam  is  at  a  higher  temperature  than  ice,  or 
steam  may  be  under  pressure  while  ice  is  not. 
Just  so  with  electricity.  When  generated  by 
friction,  electricity  is  at  high  "potential"  or 
pressure,  while  when  generated  by  chemical 
action,  it  is  at  a  low  "potential"  or  pressure. 
The  electricity  generated  by  friction  is  generally 
(although  incorrectly)  called  "static"  elec- 
199 


200  FARM    ENGINEERING 

tricity.  It  is  of  the  same  nature  as  that  which 
causes  lightning,  the  "northern  lights,"  etc., 
and  which  is  found  in  the  atmosphere.  On  a 
dry  cold  morning  as  you  comb  your  hair,  you 
hear  it  crackling  because  of  the  discharge  of 
"static"  electricity.  If  you  tear  up  a  piece  of 
paper  into  fine  bits  and  bring  them  near  a  glass 
rod  or  chimney,  or  a  piece  of  sealing  wax  which 
has  been  rubbed  briskly  with  fur,  silk,  or  wool, 
the  paper  will  jump  toward  the  glass,  and  after 
a  little  while,  if  the  paper  is  in  real  small  pieces, 
the  bits  will  fly  away  from  the  glass.  This  is 
all  due  to  "static"  electricity.  It  was  the 
only  kind  known  until  about  1792.  Then  elec- 
tricity generated  chemically  was  discovered  by 
Galvani.  This  is  known  as  "galvanic"  elec- 
tricity and  is  what  is  obtained  from  batteries. 
Afterward,  electric  dynamos  became  known 
and  the  electricity  obtained  in  that  way  is 
called  "dynamic"  electricity.  All  these  names 
are  for  the  purpose  of  distinguishing  the  method 
of  generating  the  electricity,  but  it  is  the  same 
substance  generated  each  time.  As  to  its  effects 
on  the  human  system,  if  the  exact  truth  be 
told,  no  person  can  be  sure  of  what  the  real 
permanent  effect  is   anyway,   but  there  is  no 


THE    FORMS    OF    ELECTRICITY  201 

reason  to  suspect  that  merely  the  difference  in 
the  manner  of  generation  would  produce  a 
difference  in  action.  Any  one  of  the  ways 
could  be  used  to  generate  electricity  to  kill  a 
person,  if  proper  arrangements  were  made.  Like- 
wise, electricity  generated  in  any  one  of  the  three 
ways  mentioned  is  perfectly  harmless  if  passed 
through  the  body  under  proper  conditions. 
Undoubtedly  electricity  generated  chemically 
by  means  of  a  battery  is  most  commonly  used 
by  the  medical  profession,  but  the  reasons  are 
the  ease  and  convenience  in  handling  and  the 
fact  that  the  potential  or  pressure  of  the  elec- 
tricity generated  in  the  battery  is  more  con- 
venient for  their  purpose. 

Just  what  electricity  is  no  one  knows,  but  the 
fact  is  not  astonishing.  No  person  knows  what 
anything  is.  What  is  carbon?  What  is  iron? 
What  is  oxygen?  What  is  phosphorus?  No 
one  knows  what  any  of  these  substances  is  yet, 
of  course  there  are  theories  which  explain  in 
part.  In  the  same  way  there  is  an  electrical 
theory  which  is  only  of  comparatively  recent 
origin. 

This  theory  states  that  everywhere  through- 
out the  universe,  filling  all  spaces  and  all  sub- 


202  FARM    ENGINEERING 

stances,  there  is  an  all-pervading  material  known 
as  ether.  It  is  this  ether  which  transmits  the 
light  waves  from  the  sun  through  the  enormous 
distance  between  that  heavenly  body  and  our 
own  atmosphere,  which  only  extends  a  short 
distance  above  the  earth.  It  is  the  ether 
which  transmits  heat  from  the  incandescent 
filament  within  the  vacuum  bulb  of  an  electric 
lamp  to  the  glass  itself  and  to  the  surrounding 
air.  So  electricity  may  be  merely  part  of  this 
ether  in  motion. 

We  do  not  need  to  know  exactly  the  nature 
of  electricity  in  order  for  it  to  be  of  value  to  us. 
With  it  we  may  light  our  houses,  heat  them, 
provide  power  for  all  purposes,  perform  chemical 
processes  such  as  electroplating,  and  do  multi- 
tudes of  things  of  the  greatest  use  and  impor- 
tance in  the  world's  industry. 


PART   VI 

USEFUL  TABLES  FOR  ENGINEERING 
CALCULATIONS 

I.  The  Equivalents  of  One  Horsepower. 

II.  Absolute  Efficiency  of  Various  Engines. 

III.  Weights  of  Various  Materials. 

IV.  Strength  of  Various  Materials. 

V.  The  Heating  Value  of  Fuels. 

VI.  Water  Heads  and  Corresponding  Pres- 
sures. 

VII.  Water  Powers  for  Various  Heads. 


TABLE  I 

THE    EQUIVALENTS    OF   ONE   HORSEPOWER 

Power  is  the  rate  of  doing  work.  A  small 
engine,  for  example,  can  do  as  much  work  as  a 
larger  one  but  it  will  take  a  longer  period  of 
time.  A  four-horsepower  gasoline  engine  will 
fill  a  silo  satisfactorily  in  two  days  perhaps,  but 
a  twelve-horsepower  engine  will  take  only  a 
little  over  half  a  day  to  do  the  same  job.  This 
illustrates  the  meaning  of  power.  It  has  to  do 
with  time.  We  take  as  our  unit  of  measure- 
ment the  horsepower.  That  is  the  power  which 
must  be  exerted  to  raise  33,000  pounds  a  dis- 
tance of  one  foot  in  one  minute.  This  is  called 
exerting  33,000  foot-pounds  of  work  in  one 
minute.  It  is  somewhat  greater  than  most 
draft  horses  can  exert  continually.  The  follow- 
ing table  gives  not  only  the  equivalent  of  one 
horsepower  in  foot-pounds  for  various  units 
of  time  but  also  in  foot-gallons  of  water  and 
foot-cubic  feet  of  water.  A  foot-cubic  foot 
205 


206  FARM    ENGINEERING 

means  that  a  cubic  foot  of  water  is  raised  one 
foot.  A  foot-gallon  means  that  one  gallon  is 
raised  one  foot.  The  units  given  then  mean 
that  one  horsepower  will  raise  that  number  of 
cubic  feet  or  of  gallons  a  distance  of  one  foot 
or  half  the  number  a  distance  of  two  feet,  etc. 


I  horsepowers  ::c  foot-pounds  per  second 

=  53,000  foot-pounds  per  minute. 

=  1.080,000  foot-pounds  per  hour. 

=  8f  foot-cubic  feet  of  water  per  second. 

=  528  foot-cubic  feet  of  water  per  minute. 

=  31,680  foot-cubic  feet  of  water  per  hour. 

=  66  foot-gallons  per  second. 

=  3,960  foot-gallons  per  minute. 

=  237,600  foot-gallons  per  hour. 


TABLE  II 

ABSOLUTE    EFFICIENCY  OF  VARIOUS   ENGINES 

The  mechanical  efficiency  of  most  engines 
is  about  So  per  cent.  That  is,  the  power  given 
out  by  the  engine  is  about  80  per  cent,  of  that 
put  into  the  engine.  In  a  steam  engine,  for 
example,  the  power  of  the  expanding  steam 
exerted  on  the  piston  is  the  power  put  into  the 
engine.     About  So  per  cent,  of  this  is  available 


ENGINEERING    CALCULATIONS  2C>7 

for  use  at  the  belt  pulley  of  the  engine.  There 
is  another  efficiency,  however,  which  we  may 
call  the  absolute  efficiency.  It  is  the  propor- 
tion of  the  total  power  which  could  be  exerted 
on  the  engine,  that  is  given  off  at  the  belt 
pulley.  In  the  steam  engine,  for  example,  only 
a  portion  of  the  expansive  power  of  the  steam 
is  exerted  on  the  piston.  There  is  a  tremendous 
loss  in  the  exhaust  steam.  The  same  is  true 
of  the  gasoline  engine.  There  is  a  tremendous 
loss  in  the  exhaust  and  in  the  heat  radiated 
from  the  cylinder.  In  the  windmill  there  is  a 
loss  due  to  the  fact  that  some  of  the  air  goes 
through  the  wheel  between  the  vanes  and  some 
of  it  exerts  only  a  portion  of  its  force  on  the 
vanes. 

Absolute  efficiency  of  any  engine  depends 
largely  on  the  theory  and  design  of  that  engine, 
while  mechanical  efficiency  depends  largely  on 
the  care  used  in  manufacturing  the  engine  and 
in  keeping  it  oiled  and  running  properly. 

ABSOLUTE    EFFICIENCIES 

Steam  engine 8  to  12  per  cent. 

Gasoline  and  kerosene  engines    .      .  20  to  30    "      " 

Diesel  oil  engines 30  to  40     "       " 

Windmills 10  to  25     "      " 


208  FARM    ENGINEERING 

Water-wheels 

Pelton 80  to  85 

Overshot 65  to  75 

Undershot 25  to  45 

Breast 55  to  65 

Turbine 55  to  85 


TABLE  III 

WEIGHTS    OF    VARIOUS    MATERIALS 

The  specific  gravity  of  any  substance  is  the 
number  obtained  by  dividing  the  weight  of  a 
cubic  foot  of  that  substance  by  the  weight  of 
a  cubic  foot  of  water.  To  find  the  specific 
gravity  experimentally  weigh  the  substance 
in  air  as  usual.  Call  that  weight  W.  Now 
weigh  the  substance  while  it  is  immersed  in 
water.  This  can  be  readily  done  by  tying  a 
string  to  it  and  suspending  it  by  the  string  from 
a  spring  balance,  the  substance  being  covered 
with  water  as  by  immersing  it  in  a  pail.  Call 
this  weight  M.     Then 

W 

the  specific  gravity  =■ 

W  — M 

If  the  body  is  lighter  than  water  and  so  floats, 
you  must  tie  a  sinker  to  it  after  having  found 


ENGINEERING    CALCULATIONS  209 

the  specific  gravity  of  the  sinker  by  the  above 
method.    Then  let 

S  =  specific  gravity  of  sinker 

K  =  weight  of  sinker  in  air 

N  =  weight  of  light  body  in  air 

A  =  weight  of  the  two  bodies  together  in  air 

R  =  weight  of  the  two  bodies  together  in  water 

and  the  specific  gravity  of  the  light  body  will  be 

N 


A-R-f 


To  find  the  percentage  of  different  metals  in 
an  alloy  or  compound,  find  from  the  tables  the 
specific  gravity  of  the  individual  metals.  Call 
these  S  and  R.  Get  the  weight  (W)  of  the 
compound  in  air  and  its  weight  (M)  in  water. 
Then  the  amount  of  the  metal  whose  specific 
gravity  is  S  equals 

W  — R(W  — M) 

For  example,  a  knife  is  part  silver  and  part 
steel.  It  weighs  six  ounces  (0.375  lbs.)  in  air 
and  5^  ounces  (0.343  lbs.)  in  water.  The 
specific  gravity  of  gold  used  is  15.7  and  of  steel 


2IO 


FARM    ENGINEERING 


is  7.8.     The  amount  of  gold  in  the  knife  is, 
therefore, 


0.375  —  7-8(0.375—0.343) 


7.8 

=  0.20  IDS. 

3t  gold 

I 

15-7 

METALS 

Name 

Pounds  per 
cubic  foot 

Name 

Pounds  per 
cubic  foot 

Aluminum     . 

l6l 

Lead   . 

710 

Carbon     . 

216-222 

Mercury  . 

845-7 

Copper     . 

•        549-558 

Nickel      .      . 

540-550 

Gold   .      .      . 

I200 

Platinum.      .    1 

320-I350 

Iron 

Silver 

65O-661 

Wrought    . 

.        487-492 

Tantalum 

65O-80O 

Cast 

Tin      .      .      . 

360-455 

Gray 

•        439-445 

Tungsten .      .   1 

I 60-1190 

White     . 

.        473-482 

Zinc    . 

439-449 

Steel  .      .      . 

•        474-487 

WOODS 

Name 

Pounds  per 
cubic  foot 

Name 

Pounds  per 
cubic  foot 

Alder .     .     . 

26-42 

Pine,  Pitch    . 

52-53 

Apple. 

41-52 

Hickory   . 

37-58 

Ash     .     .     . 

40-53 

Lignum  vitae. 

73-83 

Bamboo   . 

I9-25 

Linden 

20-37 

Beech . 

43-56 

Locust 

42-44 

Birch  .      .      . 

32-48 

Maple      .      . 

39-47 

Butternut 

24 

Oak    .      .      . 

37-56 

Cedar. 

30-35 

Pear   .      .      . 

38-45 

Cherry 

43-56 

Plum  .      .      . 

41-49 

Cork  . 

I4-16 

Poplar 

22-31 

Ebony 

69-83 

Sycamore 

24-37 

Elm    .      .      . 

34-37 

Walnut    .      .     . 

40-43 

Pine,  White  . 

22-31 

Willow     .      .     . 

24-37 

Pine,  Yellow 

23-37 

ENGINEERING    CALCULATIONS 


211 


STONES 


Name 

Brick 
Cement 

Loose    . 

Packed 

Set .  . 
Coal 

Soft      . 

Hard  . 
Earth 

Dry  . 
Granite  . 
Gravel 


Pounds  per 
cubic  foot 

87-137 
72-105 

"5 

168-187 

75-94 
87-112 


100-120 

125-187 

94-112 


Name 

Limestone 
Marble  . 
Masonry  . 
Mortar  . 
Mud  .  . 
Sand 

Dry      . 

Damp  . 
Sandstone 
Slate 

Soapstone 
Trap  . 


Pounds  per 
cubic  foot 

I25-I9O 

157-177 

I 16-I44 

109 

I02 

87-IO3 
II9-I28 
I24-2OO 
162-205 
162-175 
162-I7O 


MISCELLANEOUS 


Name 

Asbestos  . 
Asphaltum 
Bone  . 
Butter 
Charcoal 
Clay   . 
Glass  . 
Ice 
Leather 


Pounds  per 
cubic  foot 

125-175 

69-94 

IO6-I25 

53-54 
17-5-35 
122-162 

150-175 
55-57 
54-64 


Name 

Lime  . 
Paper 
Paraffine 
Peat    . 
Rubber 
Snow  . 
Sugar 
Tile     . 


Pounds  per 
cubic  foot 

I44-200 

44-72 

54-57 

52 

57-62 

7-8 

IOO 

87-143 


LIQUIDS 


Name 

Alcohol    .      . 
Alcohol,  Wood 
Benzine    . 
Gasoline 
Glycerine 
Milk  .     .     . 


Pounds  per 
cubic  foot 

49-4 
50.5 
56.1 
41-43 
78.6 
64.2-64.6 


Name 

Linseed  oil    . 
Lubricating  oil 
Sulphuric  acid 
Water       .      . 
Sea  water 


Pounds  per 
cubic  foot 


56 


58.8 

2-57-7 
114. 8 
62.4 
64 


212  FARM    ENGINEERING 

TABLE  IV 

STRENGTH    OF    VARIOUS    MATERIALS 

There  are  three  strengths  which  a  piece  of  any 
material  has.  These  are  resistance  to  tension  or 
stretching,  resistance  to  compression  or  crushing, 
and  resistance  to  shear  or  sliding  of  one  layer  of 
material  past  another  layer  in  the  same  piece. 
When  we  tear  a  sheet  of  paper  we  really  break  it 
in  shear  by  ripping  one  part  of  the  paper 
sideways  by  the  other  part.  The  effect  of 
shearing  is  exactly  the  same  as  though  the 
piece  of  material  were  cut  along  the  line  of 
shear. 

The  tables  given  below  are  merely  for  guid- 
ance. No  two  pieces  of  any  material  will  test 
exactly  the  same.  In  all  work  allowance  is 
made  for  that  fact  and  for  the  additional  fact 
that  we  have  no  certain  knowledge  of  just  how 
the  material  will  be  strained,  and  so  we  must 
make  the  piece,  whatever  it  may  be,  plenty 
large  enough  to  resist  all  possible  loads.  To 
make  this  allowance,  we  use  a  "factor  of 
safety."  That  is,  we  divide  the  ultimate 
strengths  given  below  by  6  or  10  so  as  to  give 


ENGINEERING    CALCULATIONS 


213 


a   safe  working   strength.     These  numbers  by 
which  we  divide  are  the  factors  of  safety. 


Tensil  strength 

Compressive 
strength 

Shear 

Material 

In  every  case  the  number  below  means  pounds  per  square  inch 

Aluminum 

wire 

30,000-40,000 

Brass  wire 

50,000-150,000 

Copper 

wire 

(hard 

drawn) 

60,000-70,000 

Platinum 

wire 

50,000 

Silver  wire 

42,000 

Gold  wire 

20,000 

Steel  wire 

460,000 

Steel 

80,000-330,000 

56,000-70,000 

48,000-60,000 

Iron 

Cast 

13,000-33,000 

80,000 

l8,000 

Wrought 

50,000-54,000 

46,000 

40,000 

Copper 

Cast 

60,O0O-7O,0O0 

40,000 

30,000 

Tin 

4,000-5,000 

6,000 

Zinc 

7,000-13,000 

20,000 

Aluminum 

15,000 

I2,000 

I2,000 

Brass 

Cast 

24,000 

30,000 

36,000 

Lead 

2,000 

Rope 

Manila 

9,000 

Hemp 

8,OO0 

Leather 

4,000 

Granite 

600 

I5,000 

Limestone 

I,000 

7,000 

Marble 

7OO 

8,000 

214 


FARM    ENGINEERING 


Material 

Tensile 
strength 

Compres- 
sive 
strength 

Shear 

In  every  case  the  number  given  below 
means  pounds  per  square  inch 

Slate     

Brick 

Brickwork  (lime  mortar) 
Brickwork  (cement  mortar) 
Cement  (Portland)    . 
Concrete  (Portland)  . 
Oak  (with  grain) . 
Oak  (across  grain) 
White  pine  (with  grain)  . 
White  pine  (across  grain) 
Georgia  pine  (with  grain) 
Georgia  pine  (across  grain) 
Cypress  (with  grain) 
Cypress  (across  grain)   . 

ISO 

10,000 

200 

40 

300 

500 

400 

10,000 

2,000 

7,000 

500 

12,000 

600 

6,000 

500 

5,000 
10,000 
10,000 
I,000 
2,000 
3,000 
2,000 
7,000 
2,000 

5>500 
800 
8,000 
1,400 
6,000 
600 

800 
4,000 

4OO 
2,000 

600 
5,000 

4OO 
2,500 

For  compression  and  shearing  use  a   factor  of  safety 
of  6.     For  tension  use  a  factor  of  safety  of  10. 


TABLE  V 

THE  HEATING  VALUE  OF  FUELS 

The  heating  value  of  any  fuel  is  measured  by 
engineers  in  units  known  as  British  Thermal 
Units,  commonly  abbreviated  to  the  form 
B.T.U.  A  B.T.U.  is  the  amount  of  heat  re- 
quired to  raise  the  temperature  of  one  pound 
of  water  through  one  degree  Fahrenheit,  the 
common  temperature  scale  on  the  thermometer. 


ENGINEERING    CALCULATIONS  215 

The  following  table  gives  the  heating  value  of 
one  pound  of  each  fuel,  and  to  get  the  heating 
value  of  any  quantity  such  as  a  ton,  multiplica- 
tion must  be  made  by  the  number  of  pounds  in 
a  ton  (2,000  lbs.). 

B.   T.    U.    PER   POUND   OF   VARIOUS   FUELS 
Fuel  Heating  value  in  B.  T.  U. 

Lignite  (brown  coal) 

Low  grade 6,347 

High  grade 7,189 

Bituminous  (soft  coal). 

Low  grade i°>958 

High  grade I4>*34 

Semi-bituminous 

Low  grade 14,121 

High  grade 14,699 

Anthracite  (hard  coal) 

Low  grade 12,577 

High  grade 13,351 

Peat  (Dried,  matted,  earthy  matter)  From  8,761  to  10,307 
♦Gasoline  (Sp.  Gr.  0.71  to 0.73)  .  .  From  19,980  to  20,520 
*Kerosene(Sp.  Gr.0.79  too.8)  .  .  From  19,800 to  20,160 
♦Alcohol  (Sp.  Gr.  0.82)     .      .     .     .  From  1 1,592  to  1 1,646 


*Notice  that  these  values  are  for  a  pound  of  the  fuel 
oil,  not  for  a  gallon.  The  heating  values  per  gallon  may 
be  calculated  from  the  specific  gravity  of  each  and  the 
weight  of  a  gallon  of  water  (8.34  lbs.). 


2l6  FARM    ENGINEERING 

TABLE  VI 

WATER   HEADS   AND   CORRESPONDING   PRESSURES 

A  column  of  water  one  foot  high  will  exert 
a  pressure  of  0.433  pounds  on  every  square  inch 
of  its  base.  In  order  to  get  a  pressure  of  one 
pound  per  square  inch,  the  column  must  there- 
fore be  2.3  feet  high.  The  following  table 
gives  the  head  in  feet,  that  is  the  distance  from 
the  surface  of  the  water  to  the  point  where 
the  pressure  is  observed,  and  the  pressure  per 
square  inch  at  the  given  distance  below.  It 
must  be  remembered  that  the  size  of  the  column 
does  not  affect  in  any  way  the  pressure  per 
square  inch  but,  obviously,  if  there  are  more 
square  inches  to  the  column  the  total  pressure 
will  be  greater. 

Head  in  Equivalent  R     d  .  Equivalent 

{  pressure  in  ,  pressure  in 

lbs.  per  sq.  in.  lbs.  per  sq.  in. 

I O.433    IO 4.33 

2 O.87     IS 6.45 

3 1.30  20 8.66 

4 1-73  25 10.78 

5 2.17  30 12.99 

6 2.60  35 15.16 

7 3-03  40 17-32 

8 3-46  45 19-49 

9 3  -9°  5° 2I-65 


ENGINEERING    CALCULATIONS 


217 


Head  in 
feet 

55 
60 

65 

70 

75 
80 

85 
90 

95 


Equivalent 

pressure  in 

lbs.  per  sq.  in. 

23  .82 

25.98 

28.15 

30.3I 
32.48 

34- 64 

36.81 

38.97 
41.14 


Head  in 
feet 

IOO 
ISO 
200 
250 
3OO 
350 
4OO 
4SO 
500 


Equivalent 

pressure  in 

lbs.  per  sq.  in. 

43-30 

64-95 

86.60 

108.25 

I 29 . 90 

151-55 
173 .20 

I94-85 
2I6.50 


TABLE  VII 

WATER   POWERS    FOR   VARIOUS    HEADS 

A  horsepower,  as  explained  in  Part  III, 
Chapter  XVII,  is  the  equivalent  of  33,000  foot- 
pounds per  minute.  Therefore  the  horsepower 
of  falling  water  will  be  given  by  multiplying 
the  number  of  pounds  weight  of  water  that 
falls  in  one  minute  by  the  distance  that  it  falls, 
and  dividing  this  product  by  33,000.  This 
horsepower  is  the  theoretical  amount  and  corres- 
ponds to  the  total  energy  contained  in  steam 
admitted  to  a  steam  engine.  However,  just 
as  only  a  part  of  the  energy  in  the  steam  can  be 
utilized  because  the  exhaust  steam  contains 
some  of  the  heat  energy,  so  the  water  which  is 
expelled  from  the  water-wheel  contains  some  of 
its     energy.     The    theoretical     horsepower    is 


2l8 


FARM    ENGINEERING 


therefore  too  large  and  it  is  usual  to  take  80  per 
cent,  of  that  theoretical  value  for  the  practical 
amount  which  may  be  obtained.  This  per- 
centage varies  with  the  head  and  with  the  type 
of  wheel  as  given  in  Table  II. 

The  values  given  below  are  for  the  fall  of  one 
cubic  foot  of  water  per  minute,  and  the  weight 
of  this  is  taken  to  be  62.4  pounds  from  Table  III. 
If  larger  quantities  are  available,  multiply  the 
horsepower  given  by  the  number  of  cubic  feet 
available.  The  number  of  cubic  feet  falling 
per  minute  is  obtained  by  multiplying  the  cross- 
section  of  the  stream  (width  in  feet  times  aver- 
age depth  in  feet)  by  the  velocity  of  flow  in  feet 
per  minute. 


Head  in 
feet 

Practical 
horsepower 

Head 
feet 

I          ....          O.OOI5 

75 

2 
3 
4 

O.OO3O 
O.OO46 
0.OO6l 

100 
IS© 
200 

5 

O.OO76 

250 

10 

O.OI52 

300 

20 
30 
40 

SO 

O.O3O4 
O.O456 
O.0608 
O.O760 

350 
400 
450 
500 

Practical 
horsepower 


1 140 

I520 
228o 
3O4O 
380O 
4560 
5320 
6080 
684O 
760O 


INDEX 


Absolute  efficiency,  207 
Air,  162 

Alcohol,  211,  215 
Alum-soap,  31 
Anthracite,  215 
Asphalt,  31,  33  . 
Asphaltum  varnish,  44 

B 

Bacteria,  89,  93 
Barbed  wire,  53 
Batteries,  154,  199 
Battery  rating,  151 
Bituminous  coal,  215 
Blocks,  Concrete,  33 
Boiler,  Steam,  99,  127 
Brake  horsepower,  126 
Breast  wheel,  133,  135 
Brick,  33,  211,  214 
British  thermal  unit,  214 
Buildings,  3 

Building  material,    12,    14, 
210,  211,  213,  214 


Capillary  action,  31,  160, 

162 
Catch  basins,  171 
Charcoal,  78 


Circulation,  8,  13,  23 
Coal,  98,  215 
Coil 

Spark,  112 

Vibrating,  113 
Cold  storage,  21 
Combustion,  1 15 
Composition  flooring,  36 
Compressive  strength,  212 
Concrete,  26,  214 

Blocks,  33 

Composition,  40 

Laying,  30 

Lean,  27 

Non-absorbent,  31 

Portland,  29 

Proportions,  28 

Puddling,  30 

Theory  of,  26 

Weight,  42 
Conductors,  Lightning,  48, 

52 
Cone  of  Depression,  61 

Copper  52,  53 

Costs  of 

Batteries,  152 

Drainage,  168 

Fuel,  99 

Horse  work,  no 

Irrigation,  183,  185 

Plowing,  98,  109 

Ram,  88 

219 


220 


INDEX 


Costs  of 

Ram-pump,  88 
Road  building,  190 
Road  maintenance,  192 
Tile,  165,  166 
Tractor,  105,  109 
Water,  185 
Waterpower,  141, 142, 

,144 
\\  ater  systems,  71 
Waterproofing,  32,  33 

Cultivation,  163,  178 

Cypress,  14,  214 

D 

Dam,  140 
Deflectors,  24 
Ditches,  174,  177,  181 
Drainage,  159 

Ditch,  165 

Tile,  172 
Drainage  of  buildings,   12, 

l7 
Dressing,  Top,  for  ice,  18 

Driers,  44 

Dynamic  electricity,  200 

Dynamometer,  124 


Edison  battery,  146,  148 
Efficiency,  10,  83,  137,  146, 

206 
Electric  battery,  145 
Electricity,  47,  199 
Electric  theory,  201 
Emery  wheels,  40 
Energy,  120 


Engine,  98,  127 

Oil,  100,  116 

Steam,  100 
Ether,  202 
Explosion,  117,  1 18 
Explosive  mixture,  116 


Factor  of  safety,  212 
Felt,  34 
Fertilizing,  164 
Filter  bed,  92 
Filter,  Sand,  75 
Fireproofing,  36 
Flooring,  36 
Foot-pound,  120 
Foundation,  15 
Fuel,  98,  214 
Furrows,  180 


Galvanic  electricity,  200 
Gasoline,  97,  215 
Gravel,  30 

Gravity,  Specific,  208 
Gravity  wheels,  134 
Grindstones,  40 
Ground  connections,  54 
Ground  water,  159 
Grout,  33 

H 

Hard  water,  79 

Head   of  water,    132,    139, 

216 
Heaters,  Orchard,  194 
Heating  value  of  fuels,  214 
Horse  work,  103 


INDEX 


221 


Horsepower,  119,  132,  205 

of  boilers,  127 
Hydraulic  ram,  82 
Hydrostatic  water,  159 

I 

Ice 

Packing,  19 

Size  of  cakes,  14 

Top  dressing  for,  18 
Icehouse,  9,  II 

Size  of,  13 
Ignition  systems,  m 
Impulse  wheels,  134 
Indicator,  121,  122 
Insulation,  13,16,  22 
Insulators,  56 
Irrigation,  178 

Skinner  system  of,    179, 
182 

J 

Jump-spark    ignition,    III, 
"3 

K 

Kerosene,  97,  215 

L 

Lamps,  151 
Laterals,  175 
Lead-plate  batteries,  146 
Lever,  125 

Lighting  systems,  149 
Lightning  rods,  47 
Lignite,  215 
Linseed  oil,  43 


M 

Macadam  road,  191 
Magneto,  114 
Maintenance,  Road,  191 
Make   and   break   ignition, 

in,  112 
Material,  Building,  12,  14, 

210,  211,  213,  214 
Mechanical  efficiency,  206 
Medical  battery,  201 
Metals 

Strength  of,  213,  214 
Weights  of,  210 
Miner's  inch,  131 
Mixture,  Explosive,  116 
Moisture,  23 

N 
Non-conductors,  22 

O 

Operation,  Costs  of 

Engine,  99 

Horse,  no 

Tractor,  108 
Orchard  heaters,  194 
Outlets,  Drainage,  174,  175 
Overshot  wheel,  133,  134 
Oxy chloride  binders,  37 


Packing 

Ice,  19 

Stores,  25 
Painting,  3,  43 
Paint  spraying,  45 
Paper,  Roofing,  15,  16,  22 


222 


INDEX 


Paraffin,  32 

Peat,  215 

Pelton  wheel,  133,  135,  136, 

143 
Plante  plates,  147 
Plow  gang,  107 
Pneumatic  equipment,  70 
Potential,  199 
Power,  120,  129,  205,  217 
Pressure,  Water,  216 
Prony  brake,  124 
Protection  of  orchards,  195 
Public  roads,  190 


Q 


Quicksand,  176 


R 

Radiation,  5 
Rain  water,  62,  66 
Ram,  82 
Ram-pump,  82 
Rating  of 

Battery,  151 

Boiler,  127 

Engine,  127 
Red  lead,  44 
Road 

Building,  190 

Cost  of,  190,  192 

Maintenance,  191,  192 
Rods,  Lightning,  47 
Roofing  paper,   15,   16,  22 
Roofs,  17 

Round  buildings,  4 
Running  water  systems,  68 


Sand,  26,  29 

Sand-clay  roads,  191 

Sand  filter,  75 

Seepage,  160 

Septic  tank,  90 

Sewage,  89 

Shape  of  buildings,  4 

Shear,  212 

Shell  road,  191 

Sills,  17 

Silo,  6,  8 

Size  of  icehouse,  13 

Skinner   irrigation    system, 

179,  182 
Spark,  117,  198 
Spark  coil,  112 
Specific  gravity,  208 
Spraying  paint,  45 
Springs,  65 
Static  electricity,  199 
Steam  boiler,  99,  127,  146 
Stones,  26,  29,  211,  214 

Artificial,  36 

Beton-Coignet,  41 

Ransome,  41 

Sorel,  36 
Storage  battery,  145 
Storage,  Cold,  21 

Packing,  25 
Strength  of  materials,  212 
Sylvester  treatment,  31,  35 


Tamping,  19 
Tensile  strength,  212 
Tile,  17,  165,  166 
Laying,  173 


INDEX 


223 


Tiling  systems,  169 
Time-saving,  4 
Thermal  unit,  214 
Top  dressing  for  ice,  18 
Tractor,  102 
Trap,  17 
Truck,  in 

Turbines,  137,  138,  142 
Turpentine,  43 

U 

Ultimate  strength,  212 
Undershot  wheel,  133,  135 


Varnish,  44,  46 
Ventilation,  9,  12,  25 
Ventilators,  18 
Voltage,  148,  152 


W 


Water 

Flow,  184 

Head,  216 

Measurement,  206 

Power,  129,  217 

Supply,  61 

Table,  61 

Wheels,  133 
Waterproofing,  26,  36 
Weights,  208 
Wells 

Artesian,  65 

Deep,  64 

Dug,  63 
Whitewash,  45 
Woods 

Strength  of,  214 

Weights  of,  210 
Work,  120,  124 


THE  COUNTRY  LIFE  PBES8 
GARDEN  CITY,   N.  Y. 


Eli 
LIS 


^m  v:- 


buSC 


Qfli  EB, 

HMHSS 


Mi      - 

,'  ^ 1 1 : ,  t  « |  tv7- 


